It's a little confusing at first, but this isn't actually calling the `add` method of the VWF inventory component. This `inventory` object is actually just the HUD element in the view. The cargo inventory node is the one with the `add` and `remove` methods. The line above, `vwf_view.kernel.callMethod( vwfInventory, "add", [ vwfObject, slot.slot ] );` is an example of how to call a method from the view.