An idea the boyfriend came up with for water is to do an H20 molecule. It was said mostly as a joke at first, but I'm thinking it could work. Mountain, fire, wispy clouds, and an H20 molecule. Probably ultimately not going to do it, but a fun idea. Since it's the closest to an element of all the pictures... it has 2 elements - hydrogen and oxygen :D And my friend would get it - one of those, know your audience things. We do theatre together, where I was running lights, and he was telling me the cues, and I was using a delta symbol, representing change in math, rather than writing out "change" for each light change. And my friend got it whereas no one else knew what in the heck it meant