I always loved the contrast between the communion party and Connie's wedding. The only holdover seems to be Frankie Five Angels, who doesn't want the "canopies", he wants his sausage and peppers. Joking around with the band, just like Mama singing at the wedding.

The other major difference is the presence of so-called society. You have the people who couldn't come to Connie's wedding because they couldn't be seen associating with the Don (but they sent expensive gifts), and Sonny spitting on the badge of the FBI guys. Then, at the Communion, law enforcement officers are plainly seen - and of course there's Senator Geary, sucking up to Michael in public, and disparaging him in private.