When I am doing model building, I try to work in an area with hard floors or very low pile carpet when possible. On hard floors it can be helpful to vacuum between working periods when you have all your parts accounted for, so that bits of plastic don't clutter up the search area if one of your parts goes flying, but I do that cleaning myself.

At least in this situation, they can find the part in the vacuum cleaner fairly easily since it looks like it would have a fairly small dirt container. I think you can see the little bit on the floor near the right side of the first frame. It seems like you should be able to see Rui and Emma's legs/feet if they are sitting up against the table.

I got one of these things to help avoid losing parts while building stuff:
https://www.hlj.com/modeling-shield-wavht-073