Looks to me that this is the graphic showing if your battery status. If you see lines going from the box (battery) to the front tires, then battery is driving the tires, If it is the other way around, then the tires are charging the battery (regenerative charging). Cant see clearly but I think there is a graphic of an engine right at the top. I think when the engine is charging the battery, you may see some lines going from the engine to the battery.
