The College of Creation bard gets Animating Performance at 6th level which allows them to animate an object and control it using a bonus action:
It can move and use its reaction on its own, but the only action it takes on its turn is the Dodge action, unless you take a bonus action on your turn to command it to take another action. That action can be one in its stat block or some other action. If you are incapacitated, the item can take any action of its choice, not just Dodge.
My question is, when the bard gets incapacitated, what does it mean for the object to take an action "of its choice?"
Does control of the object pass to the dungeon master?
For comparison, other, similar effects either explicitly state that the DM gains control. For example, Conjure elemental:
If your concentration is broken, the elemental doesn't disappear. Instead, you lose control of the elemental, it becomes hostile toward you and your companions, and it might attack. An uncontrolled elemental can't be dismissed by you, and it disappears 1 hour after you summoned it.
...Or simply dictate the conjured creature's fallback behavior. For example, any of the new Summon spells in Tasha's Cauldron:
The creature is an ally to you and your companions [and] It obeys your verbal commands [...] If you don’t issue any, it takes the Dodge action and uses its move to avoid danger.
Note that the wording of Dancing Item is also used in the Circle of Wildfire Druid's Wildfire Spirit.