Itokawa looks very different from other asteroids that have been visited by spacecraft because of its gravel-covered surface and lack of craters. However, its different appearance may be partially to do with the different scales at which we typically look at different asteroids. Here are two pictures taken at a similar scale -- about 2.4 centimeters per pixel -- of Itokawa (top) and Eros (bottom). Both show gravelly surfaces. (Itokawa has other areas that are smoother, with finer gravel, like Eros does.) Although the two still look different, they are not as different as a direct comparison between whole-asteroid images would suggest.

JAXA; NASA / JHUAPL