Agreed, at an organized meet & greet, there should always be a CM "handler" who will take photos with your camera/phone.
Character meals, a great approach I learned from the Dis (if there is no handler with the character) is to ask the character, "Do you know someone who could take a picture of us?" - when I did that, the character would find a nearby CM to take a pic.
At Tusker House, there was a gentleman CM working the area I was in; there was an adult couple at the table next to mine, and the CM chatted a bit with us and broke the ice. CM was there to take pics with the first two characters, then had to move on to the next room. When there was no handler with the other two characters coming, the man at the next table offered to take pics for me, and I said I'd take pics for them, too, so that worked out great.
I am also short with short arms and cannot take a selfie to save my life, so I totally get where you're coming from!