Peggy Drexler is the author of "Our Fathers, Ourselves: Daughters, Fathers, and the Changing American Family" and "Raising Boys Without Men." The opinions expressed in this commentary are hers.

(CNN) On Thursday, pop star Taylor Swift took the stand for women -- and herself -- when she testified that a former DJ had groped her in 2013. But is her participation in this case an act of solidarity —of sisterhood with other women who allege they have been assaulted or mistreated? Or is it just another celebrity publicity stunt?

Mueller has claimed the interaction was "jostling" in preparation for a photo, and that if he touched anything, it was her ribs. Thursday in court, however, Swift said the man had copped an undeniably intentional feel of what was most definitely her buttocks. "It was a definite grab, a very long grab," she testified. "I felt him grab onto my bare ass cheek." She tried to move away, she said, but "he would not let go."

Swift is regularly criticized for seeking publicity, whether it's through her relationships or her various feuds, and some -- like Mueller -- have questioned her motivations in this case. Which, of course, is of little surprise given how society tends to treat women who dare to stand up to the men who objectify them: They must be after something.

Swift is indeed after something: justice. And affirmation. She didn't have to take the stand on Thursday; it would have been easier not to. She might have issued a statement, let her attorneys do the talking, or settled. In fact, her mother said she at first tried to persuade her to keep quiet in order to avoid publicity and its associated humiliations. But in giving live testimony, Taylor Swift gave voice to the many women whose shame after assault keeps them quiet.

To be sure, this is a federal court trial and Mueller, like every American, is innocent unless he is judged otherwise by a jury of his peers.

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But if Swift believes she was assaulted — as she clearly does -- it is hard to view her actions Thursday as something other than brave and important. And if they generate publicity, all the better. Whatever the truth of Swift's situation, most who are assaulted don't speak up. According to the National Sexual Violence Resource Center, 63% of assaults are not reported.

Many victims don't know they have a right to do so. Others worry they won't be believed. Or they see the challenges that lie ahead: trauma in having to relive and recount, again and again, what can be — depending on the severity of the assault -- one of the most devastating, or at the least, humiliating and helpless moments in a woman's life.

Swift, though, took the stand and held her ground. She did not let others get blamed. In response to Mueller's attorney's question of whether she was critical of her bodyguard for not preventing the alleged assault, she replied, "I am critical of your client for sticking his hand under my skirt and grabbing my ass."

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She did not let herself get blamed. Questioned as to whether she tried "to get away," in the words of Mueller's attorney, she stated with poise and clarity that "I'm not going to allow you or your client to make me feel in any way that this is my fault, because it isn't."

In doing so, she spoke for millions of women. She let them know: Those gray areas others will try to tell you exist when someone touches you in a way you don't ask to be touched? They don't exist.

It is unconvincing to say this is about publicity, or showing Mueller who's boss. Even if Swift has more money and fame than the man she says assaulted her, that does not mean she's more powerful: No woman would be in the moment when a man feels a right to put his hand on her butt. Victims of sexual assault can understand this feeling.

Swift's appearance Thursday was about making the statement, to herself and the world, that whatever it was that happened was not her fault. And it's a statement she can't make enough, especially if it inspires just a single victim of assault to say it herself.