I infer from the video that she is portraying a young woman who *is* to some degree running away from ‘life as she knew it’, perhaps rashly, leaving behind (in the sink) what she has decided is a bad life, BUT she has decided to BECOME something not just different, not just a change of scenery or boyfriend, but rather BECOME something *BETTER* .
At 1 minute into the video she looks at the bulletin board and sees the USMC recruiting bumper sticker - “All women are created equal. Some BECOME Marines.” As you know, you join the Army, you commit to the Corps. Perhaps I am sucked up in the story since my father, uncle and son are Marine officers, but ... I'll take it. She decided to become better, not just different, AND (per the video) makes it to deployment, implying of course that she made it through boot camp and EARNED her spot as a grunt. Again, I'll take that.
Also I can't clearly understand the lyrics, so I'm paraphrasing ... “you'll never take away what I have become” is part of the [repeating] chorus. Amen to that. To paraphrase Ronaldus Maximus ... "some women will go through life wondering if their life mattered. A woman who has become a Marine will KNOW theirs does and did." She didn't have to make this video this way. Especially as a pop culture icon. SHE was on the obstacle course. SHE was in the mud under the barbed wire. SHE was in the cold surf, not a body double. I'll give her props for that. The music is bubble-gum pop rock. But I liked the video. thanks for making me think.
As I said, the Corps obviously thinks the video has merit, is a plus for them, because they gave her a lot of support in making it.