Very cute!! Mine often fell asleep in the high chair, it was usually the only time they stopped still so was only to be expected really!!!
Happened to mine once each. Falling asleep was an unusual occurrence at the best of times so I was a little bit peeved when they did it just like that, in a high chair. All the hours spent trying to get them to drop off at the RIGHT times, and they do it in a massively uncomfortable position at the WRONG time!