The t-shirt is a humorous way of saying that the wearer is expressive and that their feelings are often easy to read on their face. It could also be interpreted as a warning to others that the wearer is not afraid to speak their mind, even if it means they have to do it nonverbally. The t-shirt is a popular choice for people who are honest and upfront, and who don't like to beat around the bush. It can also be a good way for people to start a conversation, as it is sure to get people talking.