The problem with an ensemble cast, is it has to look like an ensemble. That’s not happening in the MCU “Eternals.” This photo says it all. While the gold of her costume and her position help establish Salma Hayek’s Ajak as a central character and the gold highlights of the costume of Ikaris tie into hers, the white costuming of Angelina Jolie’s Thena stands out.
You can see this in this still has well. There are four dark figures and one light figure.
The poster below listed Gemma Chan first and yet the images highlights Angelina Jolie.
The poster with the Eternals backlit as silhouettes best expresses an ensemble casting.
The image below that has Gemma Chan (as Sersi) highlighted only works because the color of Angelina Jolie’s Thena costume has been dimmed from a white to a pewter silver and the color of Lia McHugh’s Sprite has been changed from bright blue to at green that matches Chan’s costume. The sun setting behind them also directs the eye to the center.
The balance of color in the costuming adds to the problem of blocking and balancing the color and highlights visually to create a Golden Triangle (composition). The CGI helps to mitigate the problem, but not totally as you can see from the stills.