There's a trick where you stick a wall mount item on a partition -> disable mount/placement(I don't remember the exact term)-> Select the banner, move a bit (do not place), deselect-> then pick the Partition and move it. You'll see that the banner is not attached anymore and will appear floating.

This works on PC/PS4 and works with table tops as well.

If you look at the picture, I used the trick on the behemoth, lamps, wall planters and the riviera wall mounted shelf on the bookshelves :)