The quincunx of Selena and the Midheaven shows the need to finely coordinate career, duty, and a bright inner choice. A person may feel that the profession should be useful and honest, but not immediately understand how to combine this with money, status, competition, and the real rules of the world.
The aspect may appear through doubts: is my path clean enough, am I betraying myself, do I have the right to want success? The native may either sacrifice ambition for the sake of "rightness," or move toward status and then suffer inner discomfort. Here it is especially important to distinguish guilt from a true signal of conscience. Not every difficult choice means betrayal of oneself.