Specifying thumbnail image in new iOS 26 Games app?

Hi!

We're trying to figure out how to specify a thumbnail image that appears in search results in the new Games app. Currently the thumbnail space just shows the first three preview images from the store page (see the attached file for reference -- our game is Primrows+, at the very top of the screenshot), but other games have a custom-designed image that fills the space and looks nicer, like Welcome to Primrose Lake which you can see at the bottom of the screenshot.

I've been searching both the App Store Connect interface and the developer documentation, and I can't find where to set this image or even what this image is called.

Here is another screenshot showing the kind of artwork I am trying to create and set in app store connect for our search results:

Any help would be appreciated!

Specifying thumbnail image in new iOS 26 Games app?
 
 
Q