I contacted the person on craigslist by e-mail. This is what she told me about the bunny:
He is probably 3-4 lbs he is not neutered. He has lived next to other rabbits in cages with no problems but I don't know how they would do in the same cage. He is an outside rabbit, I have him in a dog run cage right now and his bed is a dog house, he loves the grass and room to run.
I'm a little confused about why this is so sad? He looks pretty well taken care of with room to run. And the fact that he came to the front of the cage when his owner came to take a picture is a good sign too!