Hexagram 31 of 64

☱☶ Influence

Mutual attraction, courtship.

Upper trigram

Lake · Dui

Joy and openness.

FamilyYoungest daughter
ElementMetal

Lower trigram

Mountain · Gen

Stillness and limit.

FamilyYoungest son
ElementEarth

The image

Lake above, Mountain below.

Lake over Mountain: joy and openness meeting stillness and limit.

That combination is the whole meaning of hexagram 31. Nothing about it is arbitrary — change either trigram and you get a different hexagram with a different reading, which is why the 64 form a system rather than a list.