I'm a big fan of peel and stick wallpaper. Maybe find a colorful pattern and put it on the walls in the vanity/toilet area, or maybe just the full wall seen in the first photo, next to the vanity. Then you could add some rugs and towels in coordinating colors in both "sections" of the room.

If you don't like it and/or remodel later, easy peasy removal.

Removing the light fixture is a big project unless you or someone in your home is a very good handyperson.

I can spend hours looking at wallpaper and fabric on spoonflower . com.

I know you are mentioning things you can do now while sheltering...personally I don't think its that bad, really what needs to be updated is the floor and countertop/faucets. Im not even hating that brass shower enclosure. Why aren't the medicine cabint/mirrors flush to the wall?

I would choose the same color towel bars as your faucet fixtures.

Wow! Spoonflower.com has pretty wallpaper.

The medicine cabinets were like that when we bought the house.

Canvas can be wiped easily - there are flowers and abstract, etc. - as you look into the area, there are a few surfaces - possibly neutrals that are interesting to you, could bring a serene look with simpllicity - spa !?

or pop a color good with tan/beige/white -

Tree Ring Wrapped Canvas Art Print, 18"x24"x1.5" · More Info

Linen Prewashed Lara Bath Towel, Orange, 100x140cm · More Info

Has bit of the lines that warm metal shower frame has -- can tie in? towels ok, maybe conservative side neutral -

Denzi Bath Towels, Set of 4 · More Info

"Relic II" CF Print, 30"x30" · More Info

https://www.houzz.com/products/relic-ii-cf-print-30x30-prvw-vr~146434032

Or you find a bathroom color you like - could repeat with casual heathery rug - maybe a light with blue or blue and green... I'm trying for "casual pretty"

Yoshii - Two Tone Chambray, Blue and White, Wash Cloth · More Info

Blue Hydrangea Bouquet Canvas Art Print, 24"x24" · More Info

https://www.houzz.com/products/blue-hydrangea-bouquet-canvas-art-print-24x24-prvw-vr~139454070

I saved this because to me it's not a typical color - add muted color and it's an easier blend-in.
I'm clicking houzz's pop-ups - idk if people use this in bathroom - seems to have towel's color --

Soft Twist Hand Towels, Set of 4 · More Info

Unique Loom Monterey CodexRug, 2'x3' · More Info

https://www.houzz.com/products/soft-twist-hand-towels-set-of-4-prvw-vr~117901091

For inspiration! My bathroom looked very similar and I was able to do a lot of the work myself. Some of it, like the countertop, shower enclosure and fixtures I had to hire out.

Before

After

With above nature photo, or a retro look on wall - so if you don't love bathroom, don't take accessories far into fancy - but if you do - I hope it's fab, I truly do. :)

get a cool light near the shower for that...

6 Piece Bamboo Towel Set, Spring Green · More Info

https://www.houzz.com/products/6-piece-bamboo-towel-set-spring-green-prvw-vr~137682064

Thanks for your ideas. This picture was hanging in my family room in a corner so I didn't see it very often. I like the picture for the pink, salmon, and teal colors. I was thinking of hanging it on the wall above. Do you have any suggestions on how to make this picture work or if you think it doesn't fit at all?

I love the colors...very pretty picture.

Love the picture; let it inspire your design choices in the bathroom....!

Perfect starting spot. Green towels.

https://www.ebay.com/i/382747884848?

Set the plant on the vanity between the two mirrors. Add a pretty soap and lotion set.

https://www.target.com/p/ceramic-soap-lotion-dispenser-silver-green-project-62-153/-/A-53780528

Add a pretty runner in front of the vanity. https://www.rugsusa.com/rugsusa/rugs/kaleen-zig01/Wasabi/121ZIG0170-206.html