I tend to associate some colloquial adjectives to a character. I normally say “Garfield eyes” when I am or someone else is sleepy, “Cinderella time” referring to midnight, and others. With the recent addition of fish-y look, not to mean smelly or malicious.
Did you notice that a fish, in general, has that less than blank but so serious look? While Buhi technology (to make them hibernate/sleep for up to 24 hours) was invented by a Filipino last year, something to make them giggle is far from reality. I am sure you wouldn’t want to meet fish-y (as in seriously serious) faces like theirs when the day and/or week has just begun. In a speech bubble, you want to ask “hey, why so serious?”
Have a fun and fulfilling week ahead!