I worked as an Environment artist on Saints Row in the world-building team in the year 2020.
In this particular task, my role was to use/create Decals, trims, and place props ( set dressing), to create unique Prefabs in the world layer.
In some cases, we were allowed to place assets on the Structure/building prefabs to give it a unique look.
It wouldn't be possible without the awesome team at DS Volition.