I'd prefer an interesting piece of art.

Based on what I've read on this forum, most commenters are going to recommend art in that space. Everything in the picture is neutral and since I like color I would suggest something colorful. Art is very personal so no one can really tell you what you're going to like. If you're looking for a lot of choices, try art.com. Etsy is also a favorite of people here. Mirrors are generally only used in foyers and bedrooms because that's where they're practical. One commenter on another post said she didn't want to see herself chewing and that's why she doesn't recommend mirrors in a dining area. :-)

Art in gray and brown palette to echo your chairs and rug:

"Garden Delight", Original Watercolor · More Info

Some affordable framed prints from Society6.com--get a really large size to fill about 2/3rds of the wall. These prints are created by artists who get a percentage from the site for using their work. It's a nice way to start putting up art in a new place. They come in different sizes.

Art would be really nice. Great examples from housegal.

you could do a lot more w/that little space.

consider doing a settee, or a built in bench/banquette seating, wall treatment, art, a plant.

art on the wall, and do a tall plant in the corner,,,lots of ideas. I'll post a bunch of photos for you

here are examples

big piece of art, plant. a leather or similar color setee, don't be afraid to add some color to that spot

See about getting a downrod for your light. Over the dining table, I think something a bit lower might look a bit better. 12-18" downrod would be perfect.

I'd prefer diff dining chairs. something a big more mcm, but even these spindle chairs would work. find secondhand and spray paint them. do a nice plant in the corner, and some art w/color.

but, I think I'm digging this idea the most. settee, art (sconces)

Here, perfect

This is just a setee that would go up against that wall.

if you have too much room, maybe you could do a shallow console or buffet.

similar set up.. they did some shallow bookcases or a console agasint the wall. artwork above.

Can you do similar chairs to these?? ^

floating bench off the wall.

i'm thinking you could do a bench like this too,

Walmart carries this one, so you don't have to spend a lot if you don't have a budget:

and then just add the necessary decor items around it. layered rugs, taller vase w/leaf stems, cool art, some pillows for the bench, a tall plant in the corner

https://designingvibes.com/diy-built-in-dining-bench-with-storage/

imagine there is no window and it's like your wall

I know you have a little bar overhang so tuck some stools underneath the countertop.

cute chairs^

this one too. you could even make your own artwork. look for some other types of chairs. spray paint is your friend if you're on a budget. make a bench on budget too.

I'd like some color in there but a mirror would be pretty as well. Something larger than the post-it notes, though. =D

Put something interesting on the wall by the door if you aren't going to have drapes there.

Seconding Beth on small dining bench, dramatic big art and lighting. OP's chairs and table are great and deserve a dressing up!

BANQUETTE Breakfast Room · More Info

I just wanted to say thank you all for your feedback. i am not creative or decorative and appreciate your help. so excited to put some ideas together, thank you!!!

Found two others I like.

you could even do a 'wall treatment' with wood trim, or something like this shiplap (painted any color) and install a tall shelf that goes across,,,

bench seating against that wall, but look at the 'art'.

image search "small breakfast nooks' or "breakfast nook ideas" to get some others