I'd say depends on balcony
and sims using it
also climate cause its outdoors
usually i just add in any gameplay object that seems suitable and didn't fit in the house and add some sort of romantic or less romantic hang out area
often using laterns and candles for light
in previous games gameplay was often telescope but lmao not in size range anymore so maybe like easel or yoga or meditation or even just flower arranging table or gardening pots or perhaps sunbathing towel or kiddie pool or hot tub or bathtub or...
possibilities are endless
just treat it another room
or continuation of garden
place for your sims to greet morning and nightfall