I had this idea for a long time, but I never tried it till today and the effect turns out absolutely amazing. I want to do it for every canvas >.<
I think this will benefit a lot of others so I made a video to show the effect and what to do, but it really is as simple as a very transparent canvas on the back of a stove or fridge.
I found a few more working items, if coloured black or near dark, you can get reflections on the "Long bookshelf" and also the "Corner Glass Table", if they suit your needs although they are more difficult to position. There's possibly a few more colourable items that work too when made dark.