A Human Design profile pairs two of six line positions, a structure taken from the six lines of an I Ching hexagram. The Chinese commentarial tradition has a great deal to say about those positions, and it is not what Human Design says.
What the commentaries say about these two
In the classical Yijing commentaries, the first line is the bottom of the figure, the beginning of a situation, and is generally read as obscure, undeveloped and not yet in a position to act. The third line is the top of the lower trigram, a transitional place, and the commentaries repeatedly describe it as a position of difficulty or danger, caught between the lower situation and the upper.
Those readings are traditional, they are attached to positions within the hexagram, and they are about the situation the hexagram describes rather than about a person.
What Human Design does with them
Human Design assigns each of the six lines a role name and reads a person's profile from a pair of them. The role names and their meanings are the system's own, published by Ra Uru Hu in 1987. They are not translations of the commentarial positions and should not be read as a claim about Chinese tradition.
The pairing rule
Of the thirty ordered pairs of distinct lines, Human Design uses twelve: exactly those whose lines are two or three positions apart. That constraint is structural and is described in the articles on the other profiles.