I'm not sure what to do. I click on the green bar and objects appear. If I click on the object, it appears in my inventory. I click on the booth that says "trade" on it. I drag the objects over to the left, I click Deal or Cancel and nothing happens. Sometimes when I click an object on the left, I see a message that says "the visitor disagrees." I've restarted several times, but most of the time that I do the steps I've listed nothing happens.
Viewing post in Grey (Jam version) jam comments
As I've already understood from the comments below, the game is quite unintuitive and it's no wonder you're confused.
Actually, after receiving the items in your inventory, you have to open a window and wait for a visitor (a silhouette will appear + you will hear a bell sound), then click on the booth that says “trade”. The items that the visitor brought are on top, and the price for them is below them. To trade, you have to move items (with a total value greater than or equal to the offer) from the inventory to the cells below.