Can I unsend/delete a photo/media?

When you share photos and/or videos, they are added to your storage space. If you would like to remove the media, so it will not be visible to anyone you have shared it with, choose menu, storage and delete the file(s).

If the other user is currently viewing it, it will still be shown. But, if they reopen the conversation or scroll back in a public room, the media will be a generic blurred photo.