The comic shows a realistic perspective of what sexually abused children experience.
Its bad enough that Clarissa is raped, but then its compounded by her mentally abusive elder brother(forcing her to eat warm maple syrup that reminds her of... you know), the mother ignoring/glossing it over(giving her toys to make an illusion of happiness), and manipulation(her father telling her that the family needs him to survive, or suggesting that everyone will see her as a liar, the mother calling her a tease).
Despite this, Clarissa knows what is happening is wrong and has coping mechanism(her bath ritual, invisible shield), but still feel a disdain for herself(glaring at herself in the bath mirror).
And worse still, the other people around her just don't seem to ever notice that something is wrong, dismissing her outbursts and subtle hints as either childhood silliness or just being misbehaved. Her suffering is invisible to them.
This is the reality all abused children face, everyday, without end, with no end in sight. And we walk past them everyday, never knowing what could be happening. They are invisible.
This comic is a reminder of that reality.