You could treat the space like a window seat by adding a low bookcase/bench and adding curtains. It would be a nice place to read or just put your shoes on in the morning! It'll also soften the window and warm up the space.

Have little Girls/Boys - Put in a play corner. Doll House or a small desk. Reading nook ad a small but comfortable recliner with a book shelf and a cute little rug and a side table with a light. No Kids. How about a floating desk for yourself? Somewhere to pay bills, keep a calendar and make grocery list. If you like painting or drawing an easel and some extra light could be nice in there also. If it is off the Kitchen and you lack counter space or you like entertaining ad a bar area or a coffee station. You could probably turn it into a pantry also depending on your needs and wants.

You could put a display cabinet for your visitors China ware and for special events. Or, just leave it as is as usually over some time better ideas crop up.

An oversized pot and plant? Something like this palm. It is pet friendly if that is a concern.