I've been thinking for a long time that this would be a cool feature (or mod): "Ask about mood" and then there could be an answer in the form of a notification, or maybe a speech bubble with the image from one of the relevant moodlets.
If there is even a moodlet. I think that when sims first arrive on your lot their moods are random. At least at parties I've always noticed that people arrive in a mix of moods. There's always one or two Sad or Angry or Tense.
Fortunately if you have a mirror available to them they tend to gravitate to it to calm themselves down. In one of my games with minisprite, a sim had a bedroom closet with a big mirror that we nicknamed the "Closet of Affirmation" because of how often guests would go in there to settle down :D we put the "inspirational" poster from Cats & Dogs in there too for fun
