This episode takes place on November 6, as Caleb's computer password indicates that he and Hanna's first time was on November 5, and Toby and Spencer's first kiss was the morning after (November 6). Since this is their first anniversary, it must be the following November 6.
This was be creator/producer/writer Marlene King's first episode to direct.
Marlene King's name is among other production crew members names in the mausoleum.
It is hard to count the number of petals in an hydrangea, but the counts range from 4 to 600.( Because of the different types of hydrangeas) Note that these are even numbers, which means that Toby (possibly) didn't love her
The quote written on Ali's crypt in the mausoleum says, "Unable are the Loved to die For love is Immortality." Hanna states how it sounds creepy, and Aria responds that it's Emily Dickinson.