In this scene, the executioner's helpers have lifted her patibulum, pulling her upward by her nailed wrists, until she is in a standing position as they pause to change their grip on the patibulum for the final lift. This is the last time her feet will ever touch the ground; a few inches higher, and she will be hanging by her wrists, the first time her full weight has been borne by her impaled wrists.
The executioner's helpers have to take care at this point. With the victim's wrists nailed to the face of the timber, her weight on the nails will make it tend to rotate in their grasp, which could break her wrists. Note also in the first picture how Sabina's left foot is poised so that she can go up on her tiptoes when they begin to lift, so that she can support herself for as long as she possibly can before they make her hang by her wrists.
In the second picture, we can see the top of the stipes above her; this shows how much higher they will lift her in a moment. And in the third picture, the man on the cross next to hers is visible; Sabina will be hanging like him soon.
Here are a couple of close-ups:
And here are some victims-eye views:
In the first one, she's looking a little behind her, where the executioner waits to finish his work. We can also see his helper with his hands braced and ready to lift. In the second picture, Sabina looks at Julia Lepida once again, hoping for mercy even at this point but finding none. And in the third picture, she looks down her naked body yet again. I probably shouldn't keep doing these "looking down" views, but I'm trying to capture what the victim would actually see while being crucified.