If you’ve already customised some items and wish to have exactly the same one in the other room, you don’t need to search for it in the catalogue and do the customisation all over again.

You can duplicate the existing item.

Pick the item by tapping on it and using the Duplicate icon. Or you can pick an item (or even a group of things holding Shift while selecting) and use Ctrl+C and Ctrl+V to copy and paste items!