[Feature] Display the original thumbnail of the bounding-box when a label is removed, to help the user choose the new correct label

I have searched the existing feature requests to make sure this is not a duplicate request. • Yes The feature Currently, when using the "untag" ("-" icon) feature, the first thing that comes is the list of known people. But in some cases, especially in videos because of the auto-play, it is hard to remember what the bounding box looked like before the assignment had been done, because the "featured photo" of the cluster is shown instead. So currently, the UX is way too long: • untag • create new person (with "+") • Have a rough idea of who that might be. Then realize we actually already have that label in stock • untag • retag with correct person. Ideal UX: • untagging triggers the people selection as usual, but still displays the thumbnail associated with the bounding box on top of the person's list. • instead of having only two options ("Pick a known person", or &quo…