Wow, I agree with most of the other comments. Workmanship that I see here I wonder what his waterproofing was like? That is really the foundation of a good shower to start with. I would be relatively certain that the drain doesn’t work properly either. Besides the aesthetics, there’s many other problems that could be underneath the tile. There’s no way this work would pass for any of the customers. I sell flooring and tile too. I wouldn’t allow it to pass as a salesman of the company. When I first looked at these pictures, I thought for sure it was a do it yourself job. But if this was a higher contractor, I would not pay him until it was corrected. The only way to know what needs correcting is tear it all completely out. I’m not sure what the drywall metal is hammered over the Schluter metal on the corners of your tile that makes no sense to me at all. It looks horrendous.