This is a great skyscraper based off of the “One La Salle Street Building”, but there are a few things that I would suggest adding/changing. The first one is the door, the door looks a bit too plain, I would suggest adding slightly more detail to it (e.g. A handle, or making it a push door like in the one in the “One La…” building). And the second thing that I would suggest adding is just some decoration in general. (e.g. Patterns/Materials).