Please don’t hang towels by a toilet ...

This is a bathroom. In a basement. No dilemmas. Just do what you want, based on what you have seen all your life in other bathrooms.

Like it? Leave it. Don't like it? Change it. None of this is permanent or expensive.

Why would you hide a towel in a bathroom? Is it so that people won't think it's a bathroom?

Ditto the toilet paper.

Stop stressing and have a little fun.

Is it too late to frame out the right side of the shower wall to meet the shower pan with the tile flange. If you don’t want a solid wall you can step it back & do a ledge in the shower.

No opp to bring wall to shower or create a ledge wall. Appreciate the idea though. Have to work w this space and gap.

Poorly planned shower. There is nothing you can do with that skinny space.
Hang the towel above the left side of the vanity. The only thing that should go in the space between the vanity and the toilet is a plunger and a toilet brush.

towel on left side of vanity sink. Toilet paper on side of vanity by stool and nothing in niche by shower. Easier to clean

You are right, frostyfootball. There is a 5-6” gap anticipated between the shower glass and the side wall, just enough space to hang bathrobes or bath towels on hooks....out of the way but accessible. If tile is continued up that wall, the gap will be less, of course.
I rather like the idea of hanging a piece of art at eye level in there, too. It could be a faux window showing a nice landscape or even a faux window with a faux red-haired boy’s face peeking in...depending on the taste of the owners. I think I would go for the red-haired boy.

We finished our basement last fall and your vanity looks about the size of the one we installed. Our hand towel is folded on the countertop. I didn't want to hang it on the wall because we too have an outlet where you have one and I didn't want water potentially dripping on it. My sister in law has a towel on a rug on the wall and there are always water splatters on the wall.

I agree with putting either a towel bar or towel hooks in the space to the right of the shower. Then it looks intentional.

I have a free standing toilet paper holder that is on the floor next to the toilet. Not between the toilet and vanity, but on the other side. It's not really hidden, but I mean, it is a bathroom. You don't want people having to search for the TP : )

We chose a rectangular mirror to go behind the vanity to coordinate with the rectangular sink. We got it at Menards and I cannot find it on their site right now, but it was a framed one on the smaller side, maybe 24x32 inches? We also have sconces on each side of the vanity and the original mirror we bought was too big so we had to go with a smaller one. I think it looks great. Sorry I cannot get any photos to load!

All of a sudden, Houzz is only taking smaller, resized photos. Try clicking on your photos and seeing if there is an option for easily resizing them, then load the smaller version here.

Need a wider shot to recommend anything about a mirror or hand towel placement!

OP hasn't responded to suggestions recently and I feel, IMHO, my solution was very good.

I had to leave the sconce lights off to get this picture so I apologize for the lighting quality. Just to give an idea of what we did as I posted earlier.

Leave the gap alone. If you put shelves there, no one can reach what’s on them anyway. I like the artwork idea!