I know it is was one frame, but the art looks very slick here. I like the way both Kara and Lois look here. Very nice. My assumption is this will be the belly shirt costume given that is what Supergirl wore in the Brainiac arc.
And this blurb from the article gives some context around the picture:
In the film's second story thread Superman struggles to relate to the
women in his life. As his romance with Lois heats up (in his secret
identity as Clark Kent), he worries that she could be in jeopardy if his
enemies discover their connection. And his paternal instincts drive him
to be overprotective of the teenage Kara — despite the fact that she
has super abilities on par with his.
I think this is an interesting subplot. In the prior post with the YouTube video, we heard how Superman is becoming protective of Lois, in essence keeping her in a bottle. That sort of resonance works well with Supergirl as well, harkening back to her earliest stories.
But more importantly, it makes me wonder if she will stop the solar aggressor missile now. He might have to let Kara 'free', let her show him she is ready and doesn't need to be protected in order to save the world. I thought Kara's moment in the sun (literally) might get cut out here. Now I think maybe it will be an important piece to Superman learning a lesson.
One thing that was missing from the YouTube video was a view of Superman in the movie. So I am glad that we got to see what he looks like in this article.