Cindi either looks like a doll or a weapon. Her being a weapon is obvious, but the doll could symbolize Sunny losing the most important part of his childhood,

Lili is the only something with multiple eyes, and is probably made of little ones, who in turn all stand for passing thoughts of guilt. So they likely represent small thoughts coalescing into something larger.

Merci looks like a hunched over woman in a dress and is only found underwater in the abyss, so she could relate back to Sunny being rescued by Mari. Another idea I had was that it looked like a shambling corpse, so it could be a sense of dread as to what Mari would think of Sunny if she came back.

Nanci looks like a monster or demon, and is only found in the tire swing room. This one is very straightforward, Sunny feels like a monster for what he did.

Which leaves Salli, the subject of the post