Thanks Gary and Oliver
indeed, and it took me a while to get it!
I guess with any image produced by stacking, you could argue that it never appears like this in real life - your eye would either be focused on the wall & cover-leafed hole, or the suit of armour in the room beyond.
Of course, most of the stacked images we normally see are for macros - there they seem more 'natural' because no one really sees real life with the minuscule DOF that a single close-up shot would produce. Our brains do the stacking for us.