My bf videotaped us doing for the first time, and he seemed to like it.?

Why? We've been together for 2 years, and yesterday was the first time when he took his phone and started recording what we were doing, and it sort of turn him on even more. But he did delete it after we were done. It was done at the spur of the moment. But one thing I don't get it is how he's turned on by looking at the video recording when he can look at it without the videotape either if you know what I mean, Lol. Any ideas what is it about video recording that turned him or guys like him on?