Well I am a production assistant, not exactly photo but I’ve load and unload gear, set up and break down, operate lights (and mics), assist in battery and lens changes, help set the background including moving things around, assist with problem solving, shooting as a second cam or the occasional solo shoot, talking with clients sometimes, runs to the truck or for food (almost out for gear so I’ll including that), coordinating other crew members, picking up gear and I think that’s it so far.

I also make sure the videographer (your case, photographer) doesn’t forget anything