It's the day of Ed's memorial, the service which will presided over by Rabbi Fein, the service followed by sitting shiva at Sarah's house, the redecoration process at which now completed by Tammy. Because of the solemnity of the occasion and what should be the priority of remembering Ed and supporting Shelly, issues between those in attendance should be put aside. However, as the Pfeffermans' M.O. is being self-absorbed, some may not allow their issues to be put aside even for this one day. One of those issues, long buried, was Ali's bat mitzvah that never happened. And as sitting shiva is a communal occasion, social chit chat may bring up even more issues that those affected didn't believe would be issues. During the proceedings, Josh is directly confronted by someone from his past who he didn't even know existed before this day.
—Huggo