1974 Charger with AC: Vent on "Cool" still blows some warm air?

[74ChargerSE440]

So, when I set the upper lever to "VENT" and the lover to "COOL" it still blows a little bit of warm air. Is this a leak or just how it works? Or something else?

 

[YY1]

Is the valve on the heater core hose fully closed?

Is the door from the cowl open?