For me have Earth 2 Laurel Lance, Rene Ramirez, and Dinah Drake appear.
He could have made a Funny Comment about his Earth 90 Doppelgänger. The Crisis was still related in both episodes since E90 Barry first told Barry about the Crisis that Mar Novu prepare every Earth for.
In Elseworlds, Barry and Oliver switched bodies. And we see Grant in the Green Arrow suit and Stephen in the Flash suit. And Grant is acting as Barry fanboying in the Green Arrow suit and Stephen is acting as Oliver being confused in the Flash suit.
If Stephen is acting as Barry fanboying and Grant acting as Oliver confusing, it would be hilarious.
I know it sounds confusing, what I mean is that we get to watch Elseworlds in the perspectives of Team Flash and Team Arrow.