What To Do With Eight Inches?

In a previous post, in which I shared the first draft of the floor plan, I noted that there will be about 8 inches between the edge of the left edge of the sink and the shower wall.  What to do with eight inches?  Comments included suggestions to build shelves of some kind.  So what about this:  I can make the bathroom a bit larger, so that the space will be 12 inches instead of just 8.  I will fill the entire space with a wall, and then create built-in shelves above the sink, in which to store rolled towels, baskets, etc.?

Here is a sample picture I found online.  This picture was on a blog that described how to build built-in shelves and included lots of ideas.  You can find the page here.

What do you think?  (And no, I will not have the oval mirror or or the table-top sink.

Here is my only concern.  This is a very small bathroom- only 55 square feet, plus some closet space.  Plus, by necessity it will have low ceilings- 7 feet- due to the HVAC vents running over the room.  It will feel small, so everything in the design must help it to feel larger than it actually is, so that it will feel normal.  By building out the wall to accommodate built-in shelves, I will be losing/covering available cubit footage.

Maybe I will do some research into open shelving and present a few options in my next post.