Retail Build-out at 1620 S. Michigan Showing Progress

Retail on South Michigan appears to be picking up steam again.  This time the long vacant retail space at 1620 S. Michigan appears to be getting a tenant.  The picture above was snapped last night.

What's this going to be?  We aren't sure.

It kind of looks like it could be a clothing store (maybe those are dressing rooms in the back)?  Or maybe office space?

Does anyone have any idea of what's going in here?  Or any guesses?

(Hat tip:  BO!)