If you ask "what is it like?" you're asking someone to describe something using any adjectives that will describe it, not just its appearance, for example A: "what's it like?" B: "it's easy, fun to use, and cheap."
If you ask "what does it look like?" you're just asking someone to describe the appearance of something: A: "what does it look like? " B: "it's small, red, and round"