The vast majority of us can't use a background picture because our cages are screened. I have leaf chameleons in aquariums, but that is because they are one of the very few chameleon breeds that do well in them. I built a background into the tank when I was setting it up, so no picture there either.
i use a background for my screen cage because it help prevent spraying through the cage and leaving wet stains all over my wall. it also make the chameleon feel more secure. the background i se has plants all over the backgroundand make the cage look nice
I'm a fish/pet supply buyer for That Fish Place. (A big pet store in Lancaster PA) One of the manufacturers I buy from sells aquarium backrounds with these leafy plants your talking about. You can buy specific sizes on our site at www.thatpetplace.com.
I'd like to add that you probably dont want to put the backround on either side. The back should be fine, but if your putting it on more than just the back, your starting to cut off all the air flow. Which is pretty much the reason your using a cage anyway.