Imponieren means "to impress" or "to make an impression." It's a less common verb than simply "beeindrucken" (to impress) and carries a slightly more formal or deliberate connotation of making an impact.
In the song, the woman "macht alles nur, um ihm zu imponieren" (does everything just to impress him). This word highlights her efforts and desire to capture his attention and admiration, even as she struggles with their complicated relationship. It's a key word for understanding her motivations.
This song tells the story of a woman trapped in a cycle of love and pain. She gets dressed up in her finest clothes and makeup to go out in the German city of Oberhausen. She doesn't need money, because her ex-boyfriend always pays for her. Even though their past relationship was full of "bad years" and they couldn't be happy together, she can't let go.
Every time he looks at her, she forgets all the pain and remembers only her love for him, believing he is the "love of her life." She does everything to impress him, even considering surgery, because she feels empty and lonely without him. Despite the heartache, she keeps going back, running to his house in the rain, holding on to the hope that one day, everything will finally be good between them.