Well, in the second picture I see a lone fugure who has seized a gap in the fence and has separated from other. The third picture is associated with chaotic movement of small substances, but suddenly some parts of this mass begin to move in certain direction and as the result something new is being formed and separated. The final image is more complicated. I see a part of something which was separated and fallen into a tank. In the end, the first picture, group of children had been locked in enclosed space, but due to incredible efforts they have managed to break out and one has been separated from others.

It's my opinion, however, I realize that  creating this quiz you mean something different.

Hi, thanks for your interesting videos,

I was looking forward to your pussle, but unfortunatelly, I have been too busy to be on-line these days.

With my point of view the connection between these four pictures is breakup

I am glad. Thank you very much for your interesting quizes. I am really captured by them.

Actually, those were the themes I was considering.  My main idea was 'breaking out'.  To me, the last picture makes me think about a fish stuck in a small fishbowl, wishing to be free.

I like the image of 'breakup' applied to this pictures.  What entities do you see separating?