Obviously I dont think youd know Xanxus, Fuuta and Squallo
Actually I did know that was Squallo. I've seen enough to recognize him and his hair. LOL The rest of his cohorts I wouldn't recognize on sight though.
Hibari and Chrome, I recognized like you said. Mukuro, I suspected but wasn't 100% sure if it was him.
I saw that picture this morning. Sadly, I couldn't decifer who most of the cast was. Since I don't recognize many of their 10TYL looks, I couldn't extrapolate what their 20TYL looks would be. I did recognize some of them. But not nearly enough. Still a lovely piece of artwork though.