How to suggest primary image idea on a movie - option isn't on any of the images

I'd like to correct the primary image on The Hanging Judge https://www.imdb.com/title/tt35635316?ref_=mv_close

Primary image should be this one, which is the actual cover art: https://www.imdb.com/title/tt35635316/mediaviewer/rm3607349762/?ref_=tt_ph_4 instead of the current one which is just the first image submitted. When I got to the one that should be primary and go to Edit, there is no "suggest this as the primary image" option. 

How do I do this?