The quote from Lewis Carroll's Alice in Wonderland emphasizes the importance of maintaining a genuine and consistent appearance or character, both to oneself and others. It suggests that one should strive to be true to how they want to be perceived, not pretending to be someone they are not.
The moral conveyed is to act in a way that aligns with your true self and to avoid pretenses that could cause others to see you differently than you genuinely are. In simple terms, it's about authenticity—being what you want others to see and not disguising your true nature.