1. What does it mean?
쏘쏘 writes the English expression so-so in Hangul. It is a casual response about food, a day, a result, or an experience that was acceptable but did not especially impress the speaker.
Also written or said as 쏘쏘하다, ssosso
2. The nuance
It is lukewarm rather than enthusiastic praise. Used about someone's effort or cooking, it can sound blunt, so a more specific and considerate explanation may work better.
3. Examples
“새 메뉴는 나한테 쏘쏘였어.”
The new menu item was just so-so for me.
“오늘 컨디션은 쏘쏘지만 산책은 할 만해.”
I'm feeling so-so today, but I'm up for a walk.
Sources
References support the meaning and usage. Example sentences are written for NoCapWiki.