T.S.
I am a photographer as well.
They have a great idea, but if your kid is like mine, he is sick of the camera. LOL Mine don't readily pose for me. Most people wonder why we don't have pictures of our kids--we do. We have 5 of them looking at the camera and 500 of them running. LOL
I like their idea. But what about something like a Lego thing or other type of model they can build? My boys loved anything they could build. We bought Legos for just a little above their level, then we read the directions with them and did it together. We also bought those 3D puzzles and everyone liked those. It may depend on how your boys like building things so the puzzles may or may not be a hit. But legos went well for any age and any personality. ;-)
Another idea may be to get a dress up outfit. LOL My boys at 4 were starting to get into the dressing thing. They would put on capes, swords, helmets, etc. and pretend for hours. They just loved wearing the outfits. I am not sure how that could apply to a big guy, but the 4 yr old will love it. ;-)