I doubt these are two cats but only one cat. I think it is likely either:
1. it is one video,
separated into two parts and then spliced together, where the first part stops with the cat walking behind the television and the second one starts with the cat stepping out from behind the television.
2. The video was split into two groups of individual frames, with each frame cut into halves. An animated gif was created using the frames similar to the video method.
Of course, it could also just be two cats.