India, March 15 -- Bluesky CEO Jay Graber poked fun at her rival Meta CEO Mark Zuckerberg with a quirky t-shirt she wore onstage during her keynote discussion at SXSW 2025.

Her large black t-shirt featured the Latin phrase, "Mundus sine caesaribus", which means "a world without Caesars". The original Latin phrase refers to Roman dictator Julius Caesar.

It was the female tech CEO's way of trolling Zuckerberg, who was earlier seen sporting a t-shirt with another Latin phrase "Aut Zuck aut nihil". The phrase that Zuckerberg's t-shirt bore was a play on the Latin phrase "Aut Caesar aut nihil", which means "Either Caesar or nothing".

Zuckerberg's t-shirt which bore the Latin phrase was also a large black one.

The rivalry between the two te...