There is little doubt that Zack Snyder's Justice League was completely different from the theatrical cut. In addition to being a lot longer, the Snyder Cut also made certain changes to the DC Extended Universe canon. For instance, Mera's characteristics and main storyline in Aquaman have been retconned in the film.
We only got a glimpse of Mera in 2017's Justice League and it's only when Steppenwolf comes to steal the Mother Box from Atlantis. However, she has a bigger role in the Snyder Cut, appearing in more scenes including one in the epilogue.
Before we get to the bigger picture, let's discuss Mera's general appearance in the Snyder Cut. Although the character had bright red hair and a brilliant green suit in Aquaman, her look is more subtle in the Snyder Cut. The tone of her hair and costume clearly makes it fit better with Zack Snyder's color palette.
That's not the only different thing about Mera in the Snyder Cut. She also has a slight British accent, something that is absent in Aquaman. It's a strange change but many agree it makes the character sound more royal.
The big change for Mera is revealed in her dialogue. While talking to Arthur, she shares how Queen Atlanna had raised her after her parents died. In Aquaman, Mera's father King Nereus is still very much alive and played a huge role in making Arthur the King of the Seas.
It's an interesting change considering that it would give Mera a more tragic story arc. Losing her parents would make Mera a tragic figure in the DCEU and losing Arthur, as suggested in the Knightmare sequence, could explain why she would even consider working with the likes of Batman, Joker, and Deathstroke.
For now, it is unclear if the retcon will affect Aquaman 2. After all, it has been confirmed that Dolph Lundgren will reprise his role as Nereus in the sequel. Either way, it will be interesting moving forward into the DCEU after the Snyder Cut.
Zack Snyder's Justice League is now available for streaming on HBO Max and various streaming services around the world.