I think this is a really good illustration. You rarely use such clean lines, but I think that the lines really add to the drawing, especially in combination with the subtle shadow and highlighting you've done.
I gave you 5 stars for originality because I think this is a really clever idea. It incorporates both the art, and the 'coffee' shop really well, without looking like you tried too hard.
I gave you 4 stars for Technique because the floor is not as good quality as the rest of the illustration, which is a shame. That doesn't mean it's terrible; it's actually quite good. But it kind of brings the whole thing down.
I love the quirky little speech bubbles you have used.. It gives a hint of mystery, yet allows people to guess roughly what they are saying.
In conclusion: dis b sum gud shit, yo.