"I love," said Susan, "and I hate. I desire one thing only. My eyes are hard. Jinny's eyes break into a thousand lights. Rhoda's are like those pale flowers to which moths come in the evening. [Bernard's] grow full and brim and never break."
Source: The Waves (Virginia Woolf)
This describes Susan's emotional breakdown when seeing Jinny kissing Bernard. Critics have noted that this is describing what the children are seeing, and not the appearance of the eyes. But I am having trouble understanding the imagery of the eyes here. Why are Susan's eyes being described as "hard", Jinny's as "breaking into a thousand lights", and so on?