how do you need it to function?

is it next to some entrance? is there need for people to look at themselves there or to sit down briefly? what's across-if a mirror will be put there,wll it reflect something beautiful like a view or favorite art? if yes mirror makes sense

if it doesn't really need to work like some sort of transitional spot like that, or there is nothing specific to reflect-I'd be tempted to go with a console and art over it. Or maybe tall plant and art. Or a narrow bookcase if you're into books/collections. Or just art. Go with things that'll be the most useful for the place and will bring you joy..you don't have to fill anything for the sake of it.

If it so happens that you find a small bench or ottoman or some small seating that you really love, even though you won't neccessarily use it every day-nothing wrong with putting it there too of course. It can be a small statement just like a console table, and you can pull it for conversations if needed.