[SkyPuncher]

At risk of being a bit unempathetic, your comment seems a bit obtuse.

It’s pretty clear that it’s referring to the diameter of the hail. Other flat objects are commonly used to indicate diameter. Mostly coins.

[dsizzle]

The flat part wasn't confusing, was just quibbling about the odd over-explaining of the size (fwiw in the video the person says "baseball" and "softball", and indeed I didn't see any DVD-sized ones).