The only thing I noticed is that it translates the text to all caps, and the slides were all caps, so you didn't notice anything in the video. But that's really not material; to obsess over that is missing the point that it translates text in real time between human languages using a camera.

Download it and try it. Works pretty much as advertised.

It’s also free (not the translation part but the word recognition and replacement part) so there is no excuse to not try it out yourself or getting a friend to try it out for you (should you lack an iPhone).