I do not understand the joke of the sharingan

I honestly fail to get the joke there.

It's a parody of Non Non Biyori ending theme.

Koshigaya Natsumi: "A, arette hakubishin? (Oh is that a masked musang?)"
Miyauchi Renge: "Tanuki na non! (A raccoon dog na-non!)"
Koshigaya Komari: "Araiguma desho (Isn't it just a raccoon?)"
Ichijou Hotaru: "Itachi desu yo (It is a weasel.)"

↓

Uchiha Itachi: ”Sasukeee!!!”

EDIT: See also post #1677551. Probably we need a non_non_biyori_(song) tag...