How is she stripped?

Infinity Stone Magic

Before the Tesseract was in Odin's possession, it was on the distant uninhabited planet of Clothenope. Gamora was sent by her father Thanos to retrieve the Space Stone from the Tesseract, but when she picked up, it opened a portal which sucked all of her clothes into a portal, and then flew away, landing on Asgard.

Now completely naked, she couldn't return to Thanos, lest Nebula with her larger breasts and penis have the satisfaction of being superior to Gamora at something.

Getting back in her ship, Gamora flew to the planet Asgard in search of the Tesseract. These were the days before all the Valkyries were dead, and she leaned right in their barracks.

The Valkyries saw a green naked woman enter their training area, and immediately began to take pictures.

Gamora blushed as the women warriors mocked her small breasts and dick. Her species didn't have the biological capacity to cover their genital area, and so Gamora was just **** to stand there and listen to the giggling and photo-snapping. She begged for a change of clothes, but no-one listened.

Seeing no way out of this, Gamora decided that if she was going to be humiliated, she might as well go all-out. Throwing up double peace signs, Gamora smiled and posed for the camera, as hard as she was blushing in embarrassment.