This screenshot doesn't quite do it justice but in particular when you remove multiple sites at once only one will appear selected in this confirmation dialog which makes you think nothing might happen with the others.
Either this should actually allow manipulating that list somehow or show a list in a way that it's clear that it's either all or nothing.
This screenshot shows the issue annevk noticed. I agree - this widget is misleading.
This can probably be a HTML <ol> without the list decoration and a white background.