It is important to ensure your appearance is clean and professional primarily because your outward appearance reflects your inward attitude. A polished appearance can convey respect for yourself and others, demonstrate professionalism, and enhance your credibility in a work environment.
While working hard is essential, how you present yourself can affect how others perceive your dedication and competence. Additionally, a professional appearance can foster a positive work environment and improve interpersonal relationships.
Although expressing your personality is valuable, it should still align with the professional standards of your workplace. Ultimately, while seeking approval from your boss may be a factor, the broader implications of professionalism and respect in a workplace are more significant.