Could we see the rest of the space.

If you're a neat freak, put up shelves. If not, put up shelves with doors.

As a nursery ...a hanging rod or two to display all the cute outfits..or a shelf to store diapers and other things in nice baskets

Beware lead paint.

I would leave it for now until you decide what the space will be just paint and add a tall vase for now.

You’ll never regret storage/display space. Babies accumulate lots of stuff..toys, clothes, diapers, monitors...the list goes on

Sand the vertical wall (it appears uneven), wearing a mask and goggles in case lead- based paint was used 50 years ago. If there is a rug, remove it, dump it or send it out for cleaning. Thoroughly wipe down the entire room to remove all dust. Then add a shelf system in the nook. If this will be a nursery, you want it clean clean clean.

Put your changing table close on the adjacent wall so supplies will be within reach.
I like an easily-vacuumed rug in a baby’s room.

How about a shallow closet?

Slim shelves and baskets.

If you don’t need this space for (possible) children’s clothes, then open shelves with baskets will be useful for whatever the room is used for.