Supergirl's trailer highlights Milly Alcock's updated superhero suit, and after looking at Melissa Benoist's version of Kara Zor-El, a couple of key costume details help further spotlight how different these two DC heroes are. Alcock debuted as Supergirl in James Gunn's Superman movie. There, the hero's suit was unveiled, but it was not on full display for a simple reason.
Not only was Supergirl's appearance brief, as Alcock's major role comes as the lead of the DCU's next movie, but she wore a long jacket that covered her cape and more of her suit. As such, I was excited to finally get a full look at the Girl of Steel in action in the first Supergirl trailer, and an Arrowverse comparison seemed within reason.
Milly Alcock's Updated Supergirl Suit Differs From Melissa Benoist's In 1 Way

Before Alcock's DCU debut, Melissa Benoist gave life to the most popular live-action version of Supergirl for years, leading her own Arrowverse series and starring in multiple crossover events. In that time, Benoist's Kara Danvers would come to wear several different versions of the Supergirl suit, some more classic, others more modern. There was something for everyone to like.
That said, I think the best thing to do to compare the two live-action Supergirls is to put Benoist's first version of the suit against Alcock's from the Supergirl trailer. Different from Sasha Calle's Supergirl in The Flash, both Benoist and Alcock's versions of the DC hero went for classic designs with the iconic red skirt, ditching the more modern pants look.
Why Milly Alcock's Supergirl Suit Is Perfect For Her DC Movie

While the differences are subtle, these elements just make Milly Alcock's Supergirl look more ready to throw down than Benoist's. That makes sense, as the DCU version of Kara Zor-El pulls from the comics where she had to watch thousands of Kryptonians die around her on a floating piece of Krypton that survived the planet's destruction.
The DCU Supergirl has a harder shell. Her suit is also more attuned to the movie's Sci-Fi elements. While Benoist's Supergirl had a more straightforward superhero story in the Arrowverse, though Sci-Fi elements were there, Alcock's solo movie is a full-on cosmic adventure. Her suit's design connects to that, making it perfect for a new kind of Supergirl.
