I like to hang art in unexpected places. A wonderful horizontal painting would be a splash.

We have sculptural metal wall art above our cabinets. Artisan House has many beautiful options.

With the modern, sleek kitchen, I’d look to enhance in a subtle way (or not at all); white high gloss, sculptured tile could add interest without breaking up the space.

https://www.sognaretile.com/products/porcelanosa-mosaico-matt-18x47-please-call-for-pricing?utm_source=pinterest&utm_medium=social

I'm with @JAN MOYER. Build in a soffit and paint it, maybe some outragious stools

If I were you, I'd find out who the manufacturer of the cabinets is and order/install stacked cabinets that go to the ceiling. If the sizing doesn't work, they can install a flat trim panel to close the gap. It's great to have additional storage in a condo anyway.

We had a similar situation in our condo, but our ceilings are not as high as yours, so we just had the flat trim installed in the same finish as our cabinets.

What about a wallpaper mural?

There are many designs and color schemes to choose from.

These are from an image search for floral foliage wallpaper mural, because I can envision some greenery up there.

I'd paint the alcove a bright white.

I've seen folks trim out shelving above their cabinets to create boxed/open storage spaces in the void above their cabinets, but I think that works against the simplicity of the modern design you currently have. You want to keep your surface finishes and lines minimal - open storage (especially when filled with objects) will start to look cluttered and visually distracting in your space. Sure, you could fill it with some beautiful bowls or art pieces, but honestly, it will never appear more than purely decorative. If anything, I'd box in the soffit above the wall cabinets (per Jan's suggestion) and attempt to match the veneer on your cabinets - lining the space with the more shallow wall cabinets vs. the extended refrigerator cabinet. The good news is that your island currently has this veneer installed, meaning it is likely available somewhere for this purpose. If you were able to somehow hinge this or install sliding slab doors (that match the cabinets) and create a large hidden storage area (for bulky and infrequently used items), that would be amazing, but pulling that off might be more trouble than it's worth. However, it might allow you to swap items in your existing cabinets out to make room for those items currently cluttering up your countertops. I'm not a huge fan of replacing your backsplash with tile to take it all the way to the ceiling - I think that's a bit of a downgrade given your existing simple and clean solid backsplash choice. If anything, option two would be to paint your wall in a shade that is complimentary to either the backsplash or the cabinet faces, and attempt to make that space "disappear." Whatever you do, please don't introduce another pattern or texture to this space (wallpaper or tile) - it will defeat the purpose of the clean and modern design you already have.

How about a color on that wall and ceiling above the area…accentuating the architectural interest…using a very pale color…i always like blue in cases where the windows are nearby..to bring the “sky” indoors

I would get some cool glass cabinets to fill the gap IMO too big of a gap in the design for sure and not sure why. Then you can light up the inside of the glass doors for some interest , you could frosted glass for a nice look.

My first inclination is to leave the space as is. It's not very large and really looks OK

If you want to place something up there ti has to be just the right thing. You can see below how terrible it looks when you select the wrong items. In this case, nothing would have been better IMO.

You could position a couple of LED battery operated light strips that operate on remote control and illuminate the space above.

It looks good without anything above.

Here is I found some pic with modern vases décor.

Another idea is some cabbies with décor above the cabinets. May be with clear/frosted glass doors and light inside.

I got this idea from pic above

The 'rule' is a mirror is only as good as what it reflects but something about that space said MIRROR to me..all that light coming in might really bounce around.

FWIW, someone shared this wallpaper recently, from a restaurant bathroom - it's very cheeky - drunken monkeys 😄

The site that sells it has lots of other designs too

astekhome.com

Find a long antique Asian/Chinese/Thai/Indian wood carving.

I have one that is close to 7 ft long, purchased by my parents around 25 years ago in NYC.

I like this look. The art has to be the right size with matching frames, etc. Nothing small or dark:

This isn't a kitchen cabinet, just posting for the art:

This looks as if it could be wallpaper:

My 1st thought was a birds in flight mural (DIY if handy or commissioned), or better yet find some ceramic matte black/charcoal birds hung over pink/mauve & gray clouds with uplights.

Inspiration:

https://bloomintheblack.com/diy-whiteboard-mural/

I want to apologize for the messed up link in my previous post. I couldn't seem to make astekhome.com go to the homepage. It just goes to the monkeys (there's a joke in there somewhere). Maybe it works for others, and is only doing that for me?

So now the link in this comment is working properly - at least for me it is. I can click the menu icon and go to all see 'all products' under 'collections' to see a huge array of nice designs.

https://roomdsign.com/article/what-to-do-with-space-above-kitchen-cabinets