Process block on landscape phone preview: no arrows.

Hiya: 

Just noticed a weird/bothersome thing about the process block. I was messing around with trying to get the cards centered properly--especially when adding an image to one card but not all (n.b.: it's all in the top padding)--but happened to notice this while previewing.  Is this by design? I can't seem to figure out how to move through the cards, other than to use the numbers at the bottom, which is both not on-screen initially nor intuitive. 

EDIT: it occurs to me that swiping might work, but still there doesn't seem to be much direction for the user.