Serious face on now …

They appear to be pretty random IME but 
#asknostr may be of more help. 
If you listen to fountain ⛲️ or others they **might** give hints but I honestly don’t know. https://image.nostr.build/4ddfac7e383e306ce7459483720c0d5fd54b2ba49ddf4940fd4042a83dc41975.jpg