sure looks cracked. Do the two closeups show both ends of the crack? Maybe if you take a closeup from either side it would help us figure out why it started. It's a little bit weird for a lug to crack right there unless it started at a stress riser. Don't really see any stress risers.
It's possible it started in the center. Pressed steel lugs have a weld down the center, and there often is a gap at the top of the lug