I imagine that this eulogy was challenging for Oprah* to write. After all, how do you give a eulogy for Rosa Parks? In my mind, few people could pull that off and do her justice in the eyes of the American public. Yet, if anybody is going to deliver a eulogy for her, Oprah seems like an appropriate choice. As Oprah looked to Rosa Parks as a hero, Oprah has also served as a hero to millions of people. At the same time, as she mentions several times in the speech, Oprah would likely not be as successful as she is today without people like Rosa Parks. It is Oprah's expression of this bond that brings special significance to Rosa Parks's legacy.
There are two important themes that reinforce this bond in the speech: magnitude and mobility. In terms of magnitude, this speech is full of changes in size or effect. For starters, Oprah begins this speech not as the grand public figure we usually think of, but rather as a small and innocent child. And through her childlike, naive, romanticized version of the giant Rosa Parks, we already begin to see Oprah humbling herself below someone who she sees as literally and figuratively bigger than herself. The humor in this, of course, is that Oprah grows up and meets the "petite, almost delicate lady who was the personification of grace and goodness" (para. 1). Rosa Parks is not only physically small, but she also seems humble. And so, through a little irony and role reversal, Oprah sets herself up to recast Rosa Parks as a hero who's larger than life.
Oprah accomplishes this recasting through climactic structure. Through Oprah's descriptions, little Rosa Parks gets bigger and braver. She moves from "confronting the one white man who[se] seat [she] took" to "confronting the bus driver" to "confronting the law" to "confronting history" (para. 3). As the effects of Rosa Parks's decision grow, Oprah once again becomes small and humble. So when Oprah calls Rosa Parks a "good person" who does "great things," it's almost as if Oprah is correcting herself because the label "good" is not enough.
However, there is often more to a eulogy than simply calling someone great. Another common feature of eulogies, particularly of those that Campbell and Jamieson call "national eulogies," is to transcend the border between life and death by discussing how the deceased person's memory will live on through communal values. Oprah does this beautifully through implications of mobility and immobility. Rosa Parks is best remembered for being immobile, that is, for refusing to give up her seat. This theme of immobility carries over into Oprah's allusion to the we-shall-not-be-moved mantra of the Civil Rights Movement.
What's interesting here, however, is that Rosa Parks's decision to remain immobile in a society that was also immobile somehow managed to get things moving again. "That day that you refused to give up your seat on the bus," Oprah notes, "you, Sister Rosa, changed the trajectory [emphasis added] of my life and the lives of so many other people in the world" (para. 2). Oprah's use of the term "trajectory" here is much more powerful than other words she could have chosen ("direction," "path," "course," etc.) because it implies, at least in physics, (1) some kind of force, and therefore a cause-and-effect relationship, and (2) a sense of unpredictability. In other words, had Rosa Parks not intervened, U.S. society may have followed its predictable path and nothing would be different, even today.
Oprah then takes this message of immobility and applies it to herself. Not only does she declare that she too "will not be moved," (para. 4), but she also says that she "owes [Rosa Parks] to succeed" (para. 4). What Oprah means by success isn't exactly clear, but it seems that her version of success means empowering others in the same way that Rosa Parks empowered her. If this is true, then Oprah's idea of magnitude comes full circle once again. With Rosa Parks gone, the new small and humble Oprah (and, presumably, all of us), must mature to fill the larger and more challenging role of carrying on the values she fought for. This provides a beautiful resolution to a challenging speech.
* I apologize for being informal. It just sounds awkward and unnatural to call Oprah "Winfrey" and Rosa Parks just "Parks."