Every flat surface does not need decoration. What you have there looks fine. Or leave it empty.

I would leave it empty especially because you have decor on the stairs and below on the console. Too many small pieces.

Keep empty or add a plant.

“Less is more”. For safety reasons, I do not care for any decor on stair area. I think that blank spaces are calming.

Once you have a railing it will look better leave it empty.

I would hang a long tapestry or weaving above it

No decor, it only brings attention to the “shelf”

Blank is best. Upon first glance one of those objects looks like something else entirely.

Lol there are pumpkins out for fall and a lantern!

No Amalia, not what I was referring to. On the shelf is what at first looked to be a roll of tp. Lol!

Tall Black accessories to pick up the black of the chandelier

I'd leave it empty, adding decor to it just draws more attention to the awkwardness. Without seeing a wide view of the wall next to it, I agree that hanging an interesting framed textile would look good on that wall. And it would draw the eye away from the ledge.

I think it looks great. Clean and simple. Can I ask what color you used for paint?

Benjamin moore classic grey! Although no grey in it! its literally the perfect off white eithout any yellow undertone!