Why are secrets hidden in video games called Easter Eggs?

A virtual Easter egg is an intentional hidden message, in-joke or feature in an object such as a movie, book, CD, DVD, computer program, web page or video game. The term was coined – according to Warren Robinett – by Atari after they were pointed to the secret message left by Robinett in the game Adventure.[1] It draws a parallel with the custom of the Easter egg hunt observed in many Western nations as well as the last Russian imperial family's tradition of giving elaborately jeweled egg-shaped creations by Carl Fabergé which contained hidden surprises.[2]
https://en.wikipedia.org/wiki/Easter_egg_(media)

At the time of the game's creation Atari did not credit any of its authors for their work.[6] Robinett included a hidden message in the game identifying himself as the creator,[4] thus creating one of the earliest known Easter eggs in a video game. According to Warren, a young player from Salt Lake City, Utah first discovered the easter egg and wrote in to Atari regarding it.
https://en.wikipedia.org/wiki/Adventure_(Atari_2600)