It’s even tagged as zettai ryouiki, when most of the examples are absurdly off from the correct ratio. To quote wikipedia:

The ideal zettai ryōiki ratio for the length of the miniskirt, the exposed portion of thigh, and the over-knee part of the socks is 4:1:2.5, with a tolerance of 25%.[3][4][5] The ratio has also been referred to as a golden ratio (黄金比, ōgonhi) among fans.[6]