Personification is a literary device and a type of metaphor that takes place when a thing, idea, abstract quality, aspect of nature, animal, emotion or event is given human characteristics. In the excerpt, this poetic device is used when the speaker gives the Sun the human attribute of "passing" them and refers to it as "He" as if the Sun was a person.
The stage of relational development is Experimentation, in which people interact by disclosing information about themselves. In this stage, individuals make small talk to identify common interests. Furthermore, exchanges are kept friendly and informal.
To hold the relationship progressing, I can extend the small talk to determine whether the other person is predisposed to intensify the relation. I could also try to have more profound dialogues in order to move to the next phase, Intensifying. Besides, I could cause to talk to the person more frequently and give tokens or gifts as a manifestation of greater affection. Finally, to move more straightforward to the next phase, I could also invite the person to engage in an activity together.