Helen Mirren will the cast of the Shazam movies, but one that is not uncommon for hyper-referential modern movies and television.
Mirren is a renowned British actress who has won every major acting award, but has also shown over the years that she doesn't consider herself above appearing in blockbuster franchises. In Shazam: The Fury of the Gods, Helen Mirren will be playing Hespera, a villainous demi-god who is the daughter of Atlas. Hespera is one of three daughters who will clash with Zachary Levi's Shazam, alongside Lucy Liu's Kalypso and Rachel Zegler's currently-unnamed character.
However, this casting raises interesting questions regarding the DC Extended Universe. Described early footage of Shazam: Fury of the Gods sees Shazam making a joke about seeing every The Fast & The Furious movie when talking to Hespera, an example of the youthful enthusiasm that comes from being a child transformed into a superhero and the pop-culture inflected. However, this self-referential joke creates a seeming paradox, as if Hespera exists in his world then presumably the actress Helen Mirren doesn't.
There are a number of ways this reference can be explained without breaking the DC Extended Universe's sense of realism. Perhaps in Billy's world, the Fast & the Furious series ended with Fast 7, or Magdalene was cast with a different actress. Or maybe Helen Mirren exists, and Billy is just commenting on Hespera's uncanny resemblance to her. The fact that Shazam makes this comment when talking to Hespera suggests that this is a conscious meta-textual gag on the part of the filmmakers, and therefore one which could have a rational explanation.
This kind of knowing reference to an actor's earlier works has become more common in movies along with self-referential humor . This humor was popularized in comedies in the late 2000s and early 2010s. For instance, Marvel Cinematic Universe, which references Star Wars and a number of movies and TV shows that MCU actors have starred in. Such jokes always raise the question of whether the referenced title has a different cast in-universe or if the main characters just have a resemblance to famous actors that nobody comments on.
Ultimately, these kinds of coincidences are inevitable, given the amount of pop culture references in modern blockbusters and the number of high-profile actors involved in cinematic universes such as the MCU and DCEU. Shazam: Fury of the Gods reference to Fast & The Furious in front of Helen Mirren shows that rather trying to avoid such overlap, writers are embracing it as fun Easter eggs for movie-literate viewers. While it may technically create a DCEU paradox, it is best to take the line in the lighthearted spirit of the Shazam movies.
