There are actually multiple "visible sheathed weapons" mods on Nexus, but this is the best one as of this writing. It's just a small visual flair, but it does add to the immersion of GreedFall.
This mod just makes it so all of the weapons your character has equipped are visible, even when they aren't in use. Guns, swords, axes... some of them look better than others, depending on your equipment.
Overall, it's a small but excellent touch that adds to the game's aesthetic.