A Uniqlo t-shirt features an obfuscated bash script on the back, which is an Easter egg that prints a 'Peace for All' message when decoded and run. The script is a base64 encoded string that uses ASCII art to display the message in a sine-wave pattern. The article discusses the process of decoding the script and the design of the t-shirt, which is a collaboration between Uniqlo and Akamai. The script is a unique example of a physical item containing executable code.