That is actually very easy to do if you're using mouse/keyboard. Place imitation window in Storerooom, select from Storeroom, move into position on partition and double click the Display Subcommands keybind to place. Done. (I'm not certain how awkward it might be if using a controller.)
That's what i did but i use it on stage panel to make like, hmm how to say it, stencil? Then move whole thing into place and unglue(?) panel leaving them on the partition i want them to be on. The only issue is that you need to be facing the panel at the right angle which is in front of you.

I tried to follow a glitch tutorial myself but I’m on Ps5 (was on the PS4 pro when I first tried to glitch) and it seems very hard on console unfortunately. Or I just simply suck at it, who knows! XD
So I decorated the “hard way”.
Short and simple version:
Place all items you want to float on the ground in the exact spots they need to be, place stage panel behind them, place loft in a way it covers all the hit boxes, place loft they should float up a bit. Repeat till they go to the height you want. Tedious i know but once you learn how to do it you will laugh how simple it is