Why are fishmouth shoes cannon shoes?

Why fish mouth shoes are cannon shoes is explained as follows.

Fish-mouth shoes refer to the design of the fish-mouth shape hollowed out at the top of the toe, just revealing one or two toes, also called open-toed shoes. The biggest feature of fishmouth shoes is that the toes are "looming". The whole pair of shoes shows two toes and hides three toes, which looks a little sexy and dignified and elegant, especially suitable for some women with a little wide front feet, because wearing shoes with small fish mouths will make their feet more perfect and look particularly delicate. Honey, cannon shoes refer to fishmouth high heels. Because the shape of high heels is a bit like bubbles, they are named cannon shoes.