Some users were disappointed by the 24-inch iMac redesign since it retained the chin -- so one engineer decided to redesign the case.
The iMac with it's chin moved to the rear casing
The 24-inch iMac was released in 2021 with a redesigned chassis, but it still had a small chin on the lower edge of the display. Apple placed the processor and ports in this section of the display to keep it super-thin and uniform.
An engineer called "Technology Hunter" on Chinese social media site Bilibili attempted to redesign the 24-inch iMac with a uniform display bezel. He moved the chin to the rear of the display, enabling a Studio Display-like bezel.
The modification required an all-new case machined to fit the relocated components. While the final result is striking, it isn't practical.
Having a hump on the rear of the iMac like the one in this example would require expensive and complex CNC machining. That is not so much the problem for Apple, but the waste generated from it might be. It would make the iMac much more expensive and time-consuming to manufacture.
The later-model Intel iMac famously had a bubbled-out rear case. This increased the interior volume behind the display for cooling, and accommodated the motherboard, RAM slots, penetration depth required for the ports, and more. Apple's solution for all of this in the new iMac was retaining the chin.
Apple prioritizing a thin unit in the Apple Silicon redesign meant that this bubble had to disappear. Without the chin in the new iMac, or a protrusion like in this hack, there wouldn't be room for the USB-C ports, nor the magnetic charger. And, heat from components would be directly applied to a small spot on the back of the monitor panel, shortening it's life.