Set posters for a series

[Yababakets]

You are doing the scan because some descriptions of the movie are wrong , missing or just to update the media database (libraries) ?

I use "Scan All Libraries" option in the Menu/Dashboard when the media database doesn't update automatically after I add a new movie or show. In cases where the metadata is incorrect or absent, I refresh the metadata and proceed to the "Edit Images" section, where I replace the existing poster with my custom one.