Thanks everyone!
For those interested, it is mounted on the side of a ceramic candle holder/lantern! It has a metal loop which I hang on a bracket right by a north east window, and I hang it outside on the south east facing balcony in the summer. The roots have grown through and around the holes, and I have some moss padded against the back of the roots on the inside of the holder so it doesn't dry out too quickly. If you google 'ceramic candle holder' you'll see loads of similar ones.
Culture is pretty simple - I let it dry out between watering and keep it in a bright spot during summer (it doesn't seem to mind the dull days/north east window in winter). It can take a small amount of full sun, but as you can see, the leaves will burn pretty badly if it doesn't get some shelter during the hot parts of the day. Temps range from 22-24C average during the day in summer, and around 19-21C when I bring it in in winter. Nights are cool here pretty much all year.