Rob, if you have less than 30 1/4" between the two walls, it won't work for hairdrying. The user will be banging elbows into both walls. And yes, buyers will notice how narrow it is.. i know no women who sit down at a vanity to put on make-up. I certainly don't. It's a lovely, romantic thought, but not based on reality. The days of long, elaborate cosmetic rituals are long gone. As others have said, making this a make-up vanity will not update the condo, it will date it. My choice would be to make it storage or a spot for a pretty piece of furniture, as others have suggested. If you decide a sink is absolutely necessary, please improve the lighting. And change the flooring to something waterproof and cleanable! The thought of toothpaste on the carpet makes me shudder.

I think you can still get a contemporary look with multiple pieces, but they still need to be fairly large for that space. Maybe 3 vertical rectangular canvases hung next to each other. Or if you found 40x40" pieces that you love and can find 4 that look good together, hang them in a square with 2 up and 2 down. Or how about a contemporary canvas floor cloth or tapestry hung with clips from a curtain rod with cool modern finials? You could hang one or three depending on what you find. (Odd numbers seem to work best; 2 might feel like it's dividing the wall in half.) If you are creative you can create the canvases or floor cloths yourself, borrowing ideas you find online. If you can post a picture of the wall, people might have more ideas or can do mockups. Here is a link that might be useful: Painted floor cloths - contemporary

No matter your decision, I do think you could add a little more interest to the room, bring in some color and activity. It feels very "safe" and predictable to me. But I've got a mean streak of quirk, I'd be hanging a vintage ten-speed or a bunch of random clocks in that wall.

Congratulations on your home! I would wait a little while until you change anything. You may want to paint or modify the furniture after living there for a month or two. If you do eventually choose to get new window curtains, the rods should be closer to the ceiling— buy longer panels. If you do want to paint, start getting samples and taping them to the walls since the colors will look different in varying lights (natural, lamps, dusk, evening) and it may take you a while to decide (it took me forever).