Upper trigram
☱
Lake · Dui
Joy and openness.
FamilyYoungest daughter
ElementMetal
Hexagram 45 of 64
☱☷ Gathering Together
People drawn to a common point.
Lower trigram
☷
Earth · Kun
Receptive yielding.
FamilyMother
ElementEarth
The image
Lake above, Earth below.
Lake over Earth: joy and openness meeting receptive yielding.
That combination is the whole meaning of hexagram 45. 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.