In the opening credits, there are Scrabble tiles in the lower-right corner of Mabel's window. Those letters, rearranged, spell "SILENCE".
The episode won 2 Emmy Awards for Outstanding Sound Mixing for a Comedy or Drama Series (Half-Hour) and Animation and Outstanding Guest Actor in a Comedy Series - Nathan Lane for playing Teddy Dimas.
The series' first (and quite unusual) instance of fourth-wall breaking comes at the end of the teaser, when Theo signs to the viewer. This was most likely meant to evoke the voiceovers done audibly by hearing characters.
There is no audible dialogue throughout, save for the three words spoken right before the episode ends, which includes scenes from Theo's perspective, whose deafness prevents him from hearing anything.
The funeral Mabel and Oliver attend at the Shine On Funeral Home is for Esther Maribell Balmer. Or E. M. Balmer.