Powers like Psionic Image, Thought Projection, Far Hearing, Psionic Spark and Telekinetic Grasp. Can a character standing outside a window use these pseudo-cantrips on something/someone inside the room that he can see?
You cannot use any of those powers through a pane of glass or any other transparent block. This is because all powers unless they state otherwise require line of effect. You have Line of Sight since you can see the target, but you do not have Line of Effect.
A clear line from one point to another point in an encounter that doesn’t pass through or touch blocking terrain. Unless noted otherwise, there must be line of effect between the origin square of an effect and its intended target for that target to be affected.