The Player Shop is a structure that can be used to sell items passively to other players.
Player Shops are a free-standing structure that doesn't need to be "snapped" to anything. There is a limit of 40 player shops allowed within an "Area" (I assume this is an island) and they have a total of 70 Inventory Slots. Player Shops in a Freeport have an upkeep cost that they need to maintain with gold, however, Player Shops on a Settlement have NO Upkeep requirement as far as my testing proved.
After the Player Shop is built you can use the e wheel menu to change the name of the shop and the text of the sign overhead, the name of the shop is reported in the Company Log when it makes a sale and the overhead sign is simply a cosmetic advertisement. To use the shop simply place the items within it that you wish to sell, then right-click the item and there should be a menu option to set a Gold Price or set the Gold Price the same as the last item you priced.
The Gold Price that is set by the shop owner is the price for the whole stack of items. As a buyer you are given the option to buy the whole stack for that amount, or buy individual at a price that is auto calculated by taking the total stack cost and dividing by the amount in the stack and rounding up to the nearest gold piece.
NOTE: PvE Players be aware that the Player Shop must be set to "Unlocked" so other non-Company players can access the shop's inventory and make purchases. Unlocking does NOT open the shop up for stealing, it simply allows others to access/view its inventory and the removal of any of the items still requires it's purchase.
Only the Company Owner can remove items that have no Gold price or the Gold itself within the Player Shop, so I don't think you can use the shop to 'donate' stuff by marking it with a price of 0G, but I didn't test so I can't be certain.