"Mask" is about how people hide their pain behind a happy face. The speaker looks around and sees only smiles, people enjoying the things they love. But the poem quickly points to what that picture leaves out: the scars nobody sees, voices worn rough from screaming, and eyes that have cried so much there is nothing left to cry.
The speaker sounds tired and quietly sad, but also understanding rather than angry. The last lines are the turning point. Saying that most people wear two masks, "just like me and you," pulls the speaker and the reader into the same group. It's not an accusation. It's an admission that everyone is doing it, and that the happy faces we envy may be just as false as our own.
The mood is somber and honest. The plain, conversational wording, with no ornate imagery, makes the message feel personal, like a confession shared between friends. It leaves you wondering who around you is hurting.