our australian shepherd mix would lift his upper lip like a smile. hilarious. if you want to know why dogs bark, consider how domestic dogs communicate with each other, then compare that with communication for human hearing. My daughter-in-law’s beagle barks a LOT. My rat terrier hurts my ears. Loved my husky/wolf cause she didn’t bark menacingly unless it was a threat to someone she didn’t like. Only twice in her lifetime. She whined in greeting and howled, of course. Boy do I miss her.
Our dog is probably part aussie...and will smile (only in a.m. now - she’s 13+)...but she used to only bark when strangers came...and especially if they had eye contact...and she can make people scared...now she seems to bark to order my husband to do something...it is a happy bark tho.