It's about the stakes you play for.
Masks is about volatile people, not in the sense of "prone to violent outburst", though they are sometimes. It's about people trying to find out who they are, and a world trying to tell them who they are, and how one or the other gives as they grow up. Their identity and self-determination are maybe the only things they have full control over, and as a result they're the biggest things they have to put at risk.
You can see this in GM moves like show the costs of collateral damage, or reveal the future, or make them pay a price for victory, or tell them who they are or who they should be, or bring an NPC to rash decisions and hard conclusions, or activate the downsides of their abilities and relationships.
So, if you're playing Apocalypse World and Dremmer and his boys take over the dam and start extorting your hardhold for water, or if you're playing Dungeon World and Bandit King Dremmer dams up the river and starts extorting the steading for water, you're not planning necessarily for everybody to form up into a posse and go kick Dremmer's teeth in. You probably prep a few special things about the dam, sure, but you're playing to find out what happens. The players can address the problem how they like - negotiate with Dremmer, find a new source of water, get someone or something more powerful to take care of Dremmer by bargaining or guile, whatever. Maybe they retreat in failure and life in the hardhold or steading just gets measurably worse.
But in both cases, it's reasonable to make the PCs materially responsible for solving the problem, that it won't go away on its own, and "what happens" is how they deal with the problem.
That's not really an assumption you can make in Masks, at least if you're running it out of the box with the basic assumed setting. Masks is set in Halcyon City, a place full of superheroes, some of whom are likely adult counterparts of the player characters. So, let's suppose Dremmerman escapes from jail and rallies his fellow escapees into taking over the Halcyon City Reservoir. (Dremmerman was bitten by a refugee from a post-apocalyptic future. He has some kind of unclassified mind-control power that rallies people predisposed to violence and is driven to take over municipal utilities and sometimes container ports and shopping malls.) You don't need to make the PCs materially responsible as much as you need to make them socially responsible - many people could solve this problem, but it'll look good for them if they do/bad for them if they don't. Maybe they were the ones who put Dremmerman away in the first place? He attacked Halcyon Pines Plaza when they just happened to all be there and that's how the team came together?
So you have a little more leeway to pressure the PCs into a specific course of action - having a superhero fight with Dremmerman - because the course of action doesn't matter so much as the decisions the heroes make along the way and what that says about them. You're not thinking as much about threatening Halcyon City, or about threatening the PCs' lives, limbs, or various other important things - you're thinking about challenging the PCs' identity and threatening their relationships with the people of Halcyon City. Like:
Hornet, you're flying everyone there in the Mantisjet again? Right, thought so. The dam's floodlights kick on and gunfire plays across the surface of the Mantisjet. Looks like Dremmerman's got some people levering the spotlights and taking potshots from some windows in the dam control complex. That's pretty thick concrete, but - oh, what's this? You know the Mantisjet's capable of being armed, you've fired the Scythes hundreds of times in simulators, but Mantis has never left them in when she suspected you'd be borrowing it. Until now, it seems. The controls are lighting up. Does she trust you with them now? It'd be so easy just to make a little chaos and get everyone in safely, rather than having someone risk a hail of bullets to shut things down... (Tell them the consequences, risking the costs of collateral damage).
Dusk, Mentalla warned you off of trying to probe Dremmerman's thoughts, "one psyker to another". She said she tried that while he was contained to try and understand how obviously delusional he was, but what she saw was so incomprehensible that it knocked her senseless. But hiding here, watching him get his thugs to corral all the dam workers together, he doesn't feel incomprehensible. He feels... welcoming? Nothing in this bright city feels welcoming. You can try your mind schticks on Dremmerman just fine. Well, you'll be just fine. Your doom track might not, though. (Make them pay a price for victory.)
You cast about looking for Dremmerman, Huma, but it seems like he's fled deeper into the dam. His thugs are unconscious or restrained, and since you covered them from Dremmerman's escape, the dam workers are unharmed. "Holy shit," breathes the one closest to you. "Holy shit! It's the new Huma kid. Guys, it's the new Huma kid!" They're obviously in shock a little bit, kind of babbling? But they're also saying how it's such an honor to meet you and how your legacy is the best thing that ever happened to this city. They're also not paying much attention to the rest of the team. If you just stand here and let the enthusiasm run its course, you'll be shifting your Savior up and your Danger down, and maybe that's what you want, but maybe you also want to go toe-to-toe with Dremmerman. What are you doing? (Tell them who they are or who they should be.)
The Mantisjet slows on approach to Skytower Beta - er, check me on that, that's what you all decided to call the defunct shipping company you guys are using for a base? Okay, good. Anyway, you're a little rattled, a little covered in grime and industrial chemicals, and a lot exhausted, but Dremmerman's subdued in the hold and the dam is back in working order--
--aaand that's Uncle High Ambassador's ship hovering over the dock, Skysong. There's a little fuzz before its holocomm asserts itself over the Mantisjet's controls and dear lord his sneer is palpable. "Why did I expect anything better? Rolling around in filth with the apes, are we?" Are you going to put up with this? Better question, is anyone in this jet going to put up with this? (Activate the downside of their relationships, or, heck, a combo slam with bring an NPC to hard conclusions.)
In another PBTA game, while the PCs are taking action you might be thinking about the shape of the threats and fronts in the world, thinking about how to bring what happens when they deal with Bandit King Dremmer into doubt. In Masks, you're thinking more about how the confrontation with Dremmerman has the potential to change who they are and how people treat them, not just during the confrontation itself but in the aftermath, because you have GM moves and mechanics pointed at those parts of the characters and the struggle over a character's identity is a dramatic part of the game.
