You place the object into the world. After a certain amount of time, depending on the tier of object, the little green light on its graphic will turn off (leaving only the red light on) and it'll become selectable like a farm animal. Then, like a farm animal, you use your interaction key to make it drop it's loot. In this case, that loot is pixels.

It's actually easier to think of them like a Fluffalo that never moves. They have a 'nothing going on' state, and a 'my loot is ready, use me' state.