Semiotics is the study of signs and symbols and how we interpret them. As humans, this is how we can interpret a world with limited information. Driving down the street, I might not know this neighbor but I can tell something about them if they are flying a Gadsden or a transgender flag. These are signals we are sending to the world for others to interpret. We are letting people know who we are and what we are standing for.
Of course, this isn’t just flags but the clothes we wear, the food we eat, the team we root for, the vehicle we drive, whether we choose to wear a mask or not. All signals we are sending to formulate a story we are telling ourselves of how we see the world and the story we are telling others.