The game appears to run at the same 60fps the games do and there is no way to freeze the idols while they pose. They still move (and blink) while in a pose, I suppose to mimic the concept that it's difficult to stay absolutely still (and well... not blink). If they are standing on one leg, they seem to have trouble balancing to keep the pose. All sorts of other quirks as well. It's fairly difficult to capture a pose at all the points. I suppose that's part of the charm and interest with it, so it's all good.
At times the mini-game requires a certain amount of rhythm to take identical pictures with different expressions. It is an iM@S game after all, though it's strange such a thing pops up in something like this.
As for videos, I have little idea what's out there.
Nico seems to turn up some pretty good results as a start. Some I'm sure are just merely slideshows, but there has to be something captured with a device in there. Ever since Nico's 5th anniversary the transfer speed on videos can be abysmally slow (or just disconnects all together), so I really can't check for myself at the moment.
Good luck on the search, hopefully you turn up somethin' groovy!
