Add Thumbnail Slate image to my Demo Reel

Hi,

I wanted to add a thumbnail slate image to my demo reel.  I noticed for some reason that there is only 1 choice that is provided after I uploaded my video.  In the past there have been many Slate Images to choose from.  Here are the requested URLs (I saw some of the responses to other members who have experienced the same issue) in order to have my own selected thumbnail added. 

Name URL:   https://pro.imdb.com/name/nm0896117/?rf=cons_nm_meter&ref_=cons_nm_meter

Demo Reel URL: https://pro.imdb.com/videoproembed/vi2907686937?ref_=pro_redirect_video_player

Note: If you can please select the image starting at 00:54 seconds (Wild West Chronicles Scene).   I believe it's exactly before it changes from 00:54 to 00:55 seconds.  When my mouth is closed - not open.  At the 00:55 second mark the scene changes so it's right before that.  

Thank you!