Lake AKA The Joyous
This trigram is the symbol of self-reflection (literally as self-promotion as well as deep thoughts) in the bottom position of a hexagram, and intenseness (of that reflection) when in the top position of a hexagram. One of the six 'mixed' trigrams, symbolic of the interaction of degrees of yin and yang.
In the IDM template this trigram is representative of expansive bonding and thus an overall bias to seeking wholeness (balance) through the establishments of static relationships with the outside. Note the bias to relationships with the outer rather than total integration (as attempted by the Heaven trigram).
The bonding nature reflects the sharing of space with others but retaining one's identity. This can also get into the concept of people seeing themselves in you as well as being reflections of you as they see you a reflection of them (or more so the use of a mirror as a from of defence) - the overall notion is of representation, image.
In the realm of emotions this trigram reflects sexual Love in that this trigram shares common roots with those of the trigram of Heaven where the focus is on Anger and Respect and a sense of competitive interactions. In the trigram of Lake the focus is more on cooperative interactions, Intimacy, close exchange (also gets into bartering etc) but BOTH trigrams have a more generic focus, that of REPLACEMENT, be it by eradication (anger) or replication (sex).
In the Myers-Briggs/Keirsey systems of persona classification it is linked to XSFP/Players and is mostly concerned with sensation seeking and thus forming a relationship between inner and outer to become 'one'. (balance) (e.g. Entertainers, Composers etc - it is the sensation of successfully establishing a relationship with one's audience that is seeked since this demonstrates the degree of linkage between artist and art - the notion of REFLECTION emphasises the nature of the artist)
In Chinese Five-Phase theory, Lake is linked to the concept of METAL and so the concept of EXCHANGE but more through Cooperation than competition.
The numeric link is to irrational numbers. (pi, e, etc. They show static relationships that do not change in dynamic conditions). The Peircean Category is Thirdness as Active/Explicit REPRESENTATION.