Ah, twins.
We bought this a good few years ago for our two girls to watch on trips over to Europe. It fails miserably due to the fact they both want to watch different things. And, they could never agree as to who was going to have it in front of them, and the other one starts "I can't see!" etc. It got put in the garage and we went to Comet next year and bought them individual ones with earphones. Problem sorted.
Anyway, if you want this to try out I'll dig it out and get some photos so you can see what it's like.