Little flower, big bee.
Long tongue into the nectar, anther against the forehead. This Lamium isn’t letting the bee leave town without some pollen.
But wait just a minute. This bee has a white face. The only white-faced bee I know is the male Eastern Carpenter Bee (Xylocopa virginica), but this one was rather too small for that. Or was it? There can be some serious size differences between males and females. Local conditions — food supply, weather — can also create a range of sizes among carpenter bees, as well as bumble bees.
Anyway, look at those tattered wings: I guess this one over-wintered? 
Backyard and Beyond 
I am really enjoying your close observations. Pollen on the forehead!
The smooth rear end is a good indication of carpenter bee. The bumbly fellows are fuzzy.
Is the flower henbit?
Think so.