First let me show what I meant with a screenshot:
So, when you search for a wiki in fandom, if there's a match, you see it suggested to you on the right side of the page as you can see. What I want is to update the generic wiki description and the placeholder image with something I choose.
But is that still possible? Neither editing Mobile Main Page or editing the MediaWiki:Wiki-description-site-meta page changed the description, and changing the image on Mobile Main Page also didn't have any effect.
I was looking at this page for help but it's not really helping.