what I do. 1st I save my set to drafts.
then I highlight the set and then hit the center button you'll see an invisible box that is off to the side. shrink that box to the center of your set. make it small !
-Without highlighting it- hit Center again and if you need to make bigger or smaller use the arrows to move it up or down.
then save draft again before you publish
the only time it didn't work for me was with my egg but it was big enough to see but why it was off to the side i don't know why ツ