I’ll concede you might be right about the fourth image (though I personally doubt it).

But in the first image, Leia’s clothing is already drawn in - it’s just a loincloth, and she’s naked from the waist up. The same thing is true in the second image, where she’s covering her exposed breasts with her right arm. And in the third picture, her top has partially slid off during the Imperial torture droid’s interrogation, exposing her left breast.

What we have here are definitely some sketches for NSFW Leia costumes by Ralph McQuarrie.