search Why do page thumbnails NOT show up in site Search, but blog and product thumbnails do?

I've just added the default SS /search to a clients site (ss 7.0 site) but only thumbnails from his blog are showing up on the search results page, regular pages with thumbnails added to social and media are not? Any ideas how to fix this? 

https://www.gartenbergmedia.com/search?q= swiss tour 

See the 2nd result in that link shows no thumbnail, madness! lol