https://wccftech.com/apple-once-imagined-a-mac-mini-with-a-built-in-dock-connector-for-ipod/

Apple once thought of putting a dock for the iPod nano on a Mac mini. According to new images shared is this week on Twitter, the Mac mini prototype shown features a 30-pin connector which would have allowed users to connect to the Mac without any additional cable.

The prototype images are shared by @DongleBookPro, which shows the first-gen Mac mini with a built-in dock for the iPod nano. The cutout was positioned on the top of the Mac mini and other than this, the entire machine looks pretty much identical that came out in 2005. Such docks were pretty common on speakers back in the days and Apple's iPod Hi-Fi also featured the 30-pin connector which was released a year after the Mac mini was released.