Anyone knows what effect that is?

Step through that video one frame at a time, and you will see simple straight cuts and one or two frame overlaps with about 50% transparency on the top layer. Most footage looks distorted just before the cuts or during the transitions. Mesh Warp could easily accomplish simpler distortions, and Turbulent Displace could do others. The shots are two, three, or four frames long. It's just a lot of handwork and keyframes on still images with varying overlaps and quick transparency changes.

It's been done with very short transitions, so it makes it hard to tell.  My guess would be Morph Cut in Premiere Pro.