Please spare these poor now-deceased sods your endless criticism! This was the 1920s not the "enlightened" Post-World-War-II world of huge toothpaste smiles for God's sake. Here's a historly lession for the critics:
Regarding the smile-free zone captured by photo, it is worth remembering that smiling for photos is of fairly recent origins. Earlier photographers treated these sorts of official " photograph sessions" as very serious affairs. Photography set-ups were very expensive and this was no time for frivolity (that only came into play when Hollywood popularized broad posed smiles). Subjects were routinely directed to look expressionless and keep bodily and facially still because cameras could not "process" subjects who moved. It was only dear Oriental Mr Kodak who gave us posers the freedom to act like goons when cameras clicked. Really no need for seriousness when the camera can cope with ever emerging stupidity.
As Camille Pagilia has scathingly pointed out, the almost automatic compulsion to "smile" or "say, 'Cheese'" when someone confronts you with a camera is a modern "plague" upon otherwise sensible people who would perhaps really not want to be photgraphed at all - or at most, would like to look, if not dour, then more suitably neutral.
Look at crusty and smelly old family photos - those from my maternal grandparents wedding have the "happy couple"looking like death warmed up. Was the sex really going to be that bad?