It's what she was trained to do in the Red Room, after all.
While it's a cool visual, it isn't the best part of the picture by any means.
You can see the gravity of the situation from the looks in their eyes as well as the way their hands are clasped.
While it isn't the iconic red that Natasha often sports, it's a nice easter egg to the Black Widow movie intentional or not.
The rest of the outfit looks like something straight off the movie set as well, looking less like a catsuit and more like tactical gear.
Himiyy does a great job with that here with the way she's positioned on the ground, gun drawn and ready to fire.