My edit of by eva2k0 for post-processing side challenge.
-Rough feathered selection of faces.
-RGB Curve through mask
-Circular feathered selection
-Curves through mask to create border and dark BG
-Enlarge canvas a bit to make more black space
-Resize
-USM at 88%/0.8 dia/TH = 5
-SaveAs JPEG at quality 10/10 = 383KB