I find it uncanny and although any roundish stadium is going to look like an eye due to the nature of the structure, the thinking of mass vibration amplification is unique. A lot of people are rooting and cheering, a lot of emotion playing out in a confined space.

The Romans and Greeks built colosseums and amphitheaters that were acoustically perfect. A person speaking in a normal conversational volume in the center could be heard clearly throughout, whereas the din and murmur from the crowds were dampened.

If we remember sound is a form of vibration, it stand to reason other types of vibration could be similarly amplified.