The scar Nichols has is not make up; it's actor Natasha Lyonne''s own from when she had open heart surgery.
When Nicky complains to Red (Kate Mulgrew ) about not being chosen to campaign, she states "I thought I was your 'Spock'; your right hand." This is a reference to the Star Trek (1966) character, Spock. Kate Mulgrew portrayed Captain Janeway in the Star Trek series, Star Trek: Voyager (1995).
Matt McGorry (John Bennett) & Alysia Reiner (Natalie Figueroa) also worked together on How to Get Away with Murder (2014) as Asher Millstone & D.A. Wendy Parks respectively.