See current custom layout:
I wanna decide if I use 1 landscape format image per row
OR
2 portrait formats next to each other per row.
OR
if I wanna insert a custom "animated logo" (linked to the project by individual set link)

:-)

On the desktop version e.g. my thumbnail for project #1 image is landscape format OR e.g. custom made linked animated logos work fine, BUT on the mobile device I wish I could insert a (different!) second thumbnail for project #1 but in portrait (or my own image ratio) format. Different ratio won´t do it cause the "sweet spot" of the image won t always be the best and I might wanna change/select my own detail/close-up OR maybe another motif.

So to answer your question:
I d like (see screenshot) another option to put a second thumbnail here. Would be awesome. This might would come of course as well with another option for the thumbnail mouse over for this second thumbnail.

(also I guess when I first used lay theme the thumbnail grid was not there yet?? hahah ;-))

thanks for this smooth conversation & problem solving!

if you use the project thumbnail gridm you do already have this setting

which you can use specifically for phone,
if you click the phone symbol here