Hens do have droopy earlobes (some more than others), but a roo will almost always have considerably longer earlobes than a hen of the same age if they are both sexually mature.
A better indicator would be checking and comparing their hackle and saddle feathers. Your roo on the left has some nice and easily visible saddle feathers. The angle of the photo doesn't show the saddles on the one of the right, but if they are the same, then you have two roos.