A Musical Mishap
In popular music, a common phrase is "Clap your hands!" We clap to express satisfaction with a performance or to encourage others. It's a positive and uplifting message for a T-shirt we can support.
However, clapping your hands differently is something one would undoubtedly want to avoid. This shirt has fallen victim to a significant translation error. We can safely assume that the wearer does not intend to encourage those around him to engage in unpleasant activities like "clapping their hands."