In one scene Dr. Ledgard is shown working on a bonsai tree. Bonsai is the art of creating spectacularly twisted dwarf trees, contrary to their natural patterns, by manipulating their nutrition, growing conditions and with ruthless pruning. This mirrors his ongoing experiment with Vera.
When Dr.Ledgard enters his bedroom, the book "The Selfish Gene" by 'Richard Dawkins' is open on his bed. The book's naturalistic approach is that a human being is a gene's way of making a new copy of itself; humans have limited say in the matter. This may reflect on Ledgard's state of mind in manipulating Vera. (The book is acknowledged in the credits.)
After a few days of shooting, Pedro Almodóvar had a conversation with Antonio Banderas in which he told Banderas that he needed to drop all of his ticks as an actor, because the director wanted a really restrained character and the actor was playing him in a more typical psycho way.
One of the books in Vera's room is "Angel at My Table" by Janet Frame. This book is an autobiographical account of how she grew from someone, in the author's own words, "as sexless as a stick of wood", to an appreciation of her own sexuality. (The book is acknowledged in the credits.)
The trivia items below may give away important plot points.
Ledgard calls his synthetic skin 'Gal' after his first wife. The name Gal is short for Galatea, who in Roman Mythology was a statue made by the gifted sculptor Pygmalion. The statue was so perfect that Pygmalion fell in love with his own creation and Venus granted his wish to bring her to life.
Knowing they were playing the same character, Jan Cornet and Elena Anaya started to spend time together, so they both could decide on the physicality of Vicente/Vera, but without telling anyone on the crew. They even went jogging together so their bodies would naturally mimic each other. They knew they were doing a good job when one day of shooting Pedro Almodóvar noticed they walk similarly and told them so.
When Ledgard is challenged by his colleague near the end of the film, Vera defends him. She also says her name is 'Vera Cruz'. 'Vera', the name given her by Ledgard, means Truth, but 'Vera Cruz' means True Cross; an ironically appropriate name on many levels.