I use this site on my iPad and occasionally my phone, and have so far been unable to find a way to rearrange buildings and decorations for scenes. I know for a laptop or computer, you would use the arrow keys but alas, such things are not in my possession

@Dellavayi

I mainly play on my ipad, and while you can’t drag them, touch controls work! After adding the items to the scene, hit ‘place’ and touch where you want them to go. If you want precision you’ll have to do a bunch of taps really close together to find the right spot, but it’s certainly doable.

@Wolf
Oh my goodness!!! You have opened my eyes! I can’t believe I’ve looked past that button for so long!
Thank you so much!!!

Just so you know, that's the same way it works on a computer, too. You can't drag items, you have to click where you want them to go, and if you want to move it just a teeeeeeeny bit, you have to click again and again until you hit the spot.

@Akkhima on the computer once youve placed something you can use the arrow keys to adjust its position minutely