How or what?
How does it look like?
What does it look like?
'What does it look like' is the correct version of the question because we are asking for a description of something and so we use what.
It can be confusing though because a similar question can be asked using how:
How does this dress look on me?
In this case how is correct because we are asking for the condition of something.
Does it look good or not?
Q: What does the dress look like? (describe the dress)
A: It's a black, floor length dress with a belt at the waist.
Q: How does the dress look on me? (condition of the dress, does it look good?)
A: The dress looks really good on you. You always look good in black.
How asks for the condition of or manner in which something has happened or something will happen.
How did you break the window?
How did you make this soup?
How are you going to get to Spain?
What asks for a description of something or about something.
What did you use to break the window?
What did you put in this soup?
What form of transport are you going to use to get to Spain?