Hi,
I have the same challeges with Icon Grid.

We are not looking for a general explanation from the mentioned thread (where most is in “private replies”) but a concrete solution to this problem:

How to show an image (svg, png, jpeg) instead of the icon on the front of the Icon Grid.

This could be (ideally) be solved by simpy adding the flip-side setting options as options for both the front side and flip side.

(A general UX analysis would benefit the theme a lot…)