Use an item's menu to remove it from the room. Removing an item makes space for something new.
Undo trash
For most room items, Here offers Undo after you trash them. Trashed items are kept for up to 24 hours before they are permanently removed. Restore an accidental deletion as soon as possible.
Photo Booth polaroids are an exception: deleting one removes the photo permanently, with no Undo.
Lock an item
The owner or an admin can lock an item to stop members changing it. They can unlock it again from its menu. Room settings also have Lock All and Unlock All controls.
If you cannot edit an item, it may be locked, or you may be a guest. Ask the owner or an admin before removing shared content.