The speaker starts with a small moment: trying to draw someone and ending up daydreaming about drawing one particular person. From there the fantasies pile up. She imagines being adored, flaws and all, being treated like a princess, and being watched and wanted. Even her songs and writing start bending toward this person, though she never meant them to.
What makes the poem interesting is how quickly she talks herself out of it. She insists she isn't in love, that this is just a stupid little crush, and that she only feels it so strongly because it's been a long time since the last one. Then comes the honest turn: she's attracted to what she knows of the person, to the idea of them, and really to the idea of love itself.
The mood is wistful, a little embarrassed, and quietly self-aware. The ending, where she plans to hide the feeling and wait it out, feels both sensible and sad.