Student or Learner
what is the difference between 'how does it look?' and 'what does it look like?'
Interested in Language
not a teacher
Both questions ask for a description of the appearance of the subject.
The 2nd question suggests giving an a example of another object which is similar in appearance to the subject to make it easier for one to imagine how the latter looks.
how does it look - rate its appearance (poor, fair, good)
what does it look like - describe it by comparing it to something else