The changes affected the shadow display system.
One of the players in Dead Redemption 2 drew attention to downgrade graphics with patch 1.06. He noted that the shadow display of ambient occlusion has deteriorated in westerns. This system allows you to give volume to different recesses in 3D-objects, which represent a complete model. For example, the shadows between bricks in a brick wall.
User Darealbandicoot compared two images before and after downgrade. On the right picture you can see that the shelf behind the bartender slightly lost in detail. Also, less deep shadows are visible on the wooden ornament framing the stand.
It is not yet known what the downgrade is about. Netizens noted that the developers have simplified the shadow system back in patch 1.03. At the same time, it is not explicitly indicated in the patches that the authors made some graphic changes. According to some players, the downgrade only affected the version for the PlayStation 4.
Red Dead Redemption received high marks from the press, including for its graphics and technical solutions Rockstar. The average score of the game on Metacritic is 97.