Once you have downloaded Thumbnails and Boxarts for MAME in Retroarch, you will notice that only the Boxarts are displayed. This guide will show you how to display the in-game snapshots instead of the boxarts.
Personally, I don’t care about the Title screen or the Boxart.
Retroarch shows boxarts in game list by default, that’s not telling about the game
When I want to play Arcade games, I want to see what the game actually will look like, right away:
A snapshot of the game in Retroarch game list is more telling
When you download the thumbnails within Retroarch, it will download only the necessary for the games that you have, under:
RetroArch-Win64\
thumbnails\
<SYSTEM>\
Named_Boxarts
Named_Snaps
Named_Titles
Retroarch will show the Boxarts only, no way to change that.
How to show Snapshots instead of Boxarts in Retroarch
Very simple:
under RetroArch-Win64\thumbnails\<SYSTEM>\ : swap Boxarts with Snaps or Titles if you prefer: