Misgraded petite sirloin?

I was cuttina USDA Choice ball tins todav and came across one that had ridiculous inter-muscular marbling. It reminded me of the pictures of A5 Wagyu that I've seen. The 2nd picture is how they normally look: quite lean

'm fairly new to cutting – is this kind of marbling in a petite sirloin considered desireable? I bought some for myself to try at home because Im curious.

Thanks!