Found the bigger version
And the text that goes with it-
"As the car travels through the air, some of the airflow is directed around the nose and to the sides of the front fenders and wheelwells. If the sides of the nose are angled from a top view, the air will flow out away from the wheelwells and create a very low-pressure area just outside the wheels. The air under the hood is mostly stationary, and some of that air rushes to the wheelwells to fill the void created by this suction. This creates a low-pressure area under the hood, and the pressure differential between the top and bottom creates the downforce needed to provide more grip in the front of the car."
From-
Aerodynamics - Tech & Definitions - Circle Track Magazine
Probably not 100% true for many FWD cars (like mine) since the wheel well is separated from the engine compartment, but the idea for the outside flow is relevant.