The only things I can think of are:
Fresh cut flowers
Pot plants (u can get some sort of water retention stuff so u don't have to water them often)
An air purifier that u can put some floral scent on like lavender
Dried or fake flowers (there's really cheap ones that look very real)
Bonsai, though u'd have to get a variety that will survive indoors.
One of those large tubes with colourful fake fish in that bob up and down - these look fantastic & very real, great to use at night
A biscuit tin garden - basically a large biscuit tin (plastic or metal), a few holes punched in the bottom, put on a plastic tray, fill the tin with fine compost & plant up with mosses, ferns, daisies, alpines etc (small growing plants. It won't last all year round, but makes a lovely green growing area.
A living wall - use a long tray/series of trays for troughs & the troughs (wilko do them for a few quid), some trellis (as high as u want) and place them against an indoor wall (I think it's recommended u actually fix them to the wall - I saw it done on Gardeners' World a few years back). Fill the troughs with compost & select suitable plants (like vine tomatoes in spring/summer)/clematis, passionflower/jasmine etc. If the room is well lit, they should grow ok & flower.
Don't mix compost with soil from the garden - pests get in that way.
I hope that inspires u some!