A “thwop” is supposedly the sound when you serve mashed potatoes, like when you throw it off your spoon. So, you can word it as a serving of mashed potatoes or the sound of serving mashed potatoes.
Whose shoes are these in the middle of the kitchen floor? would be the correct way to state this question.
The montage set to upbeat music. People like to see happy people so that would work the best.