At about the 1:25:44 mark, Rachel is walking through the baby store dream and you can clearly see the three dragon tattoo on Emilia Clarke's right wrist from her Game of Thrones role.
There is a mid credit scene featuring an interview with the founder of Pegazus.
Eliza, the AI therapist, is named after a natural language AI program developed in the mid 60s. ELIZA the program was famously run as a Rogerian style psychotherapist, a method that reflects the patients words back at them. Eliza the movie therapist uses the same method and the dialog, with few exceptions, is very similar to the output of the program.
The nature pod Rachel visits is located at Tour & Taxis in Brussels