How to filter out certain attributes when searching (ie smiling)

To find stock photos of people without smiling, try using these tips liek Search for Specific Phrases: Use terms like “serious expression,” “neutral expression,” or “professional portrait and Use Filters: On stock photo websites, apply filters for emotions or expressions, if available.

Mini Militia  App Lock 

All in all, in my view there is a severe lack of motifs with ordinary people who are not jubilantly happy - both privately and in business. Apparently there isn't that much demand for them ...

Thank you all for your suggestions. I'm trying to figure out a better way to ask. 

Try putting 

friends coffee

into the search, everyone is laughing or smiling like they just won the lottery. How do I search for people just having coffee? I mean a smile would be ok, but I don't want anger/frowning/stern...

Unsmiling ? Serious, sad, somber, close-mouthed...

You are applying correct method but somehow I am noticing we do not use "smile" much on keywords attached to images, I do suggest that you be more descriptive on non-smiling keywords i.e. frown, sad, angry - this will give more desirable result.  I will by the way convey this issue to product management.

Regards,

Maybe try 'stern expression," "angry expression," "stoic expression," etc?