project moon really loves creating parallels. several abnormalities are either explicitly or implicitly based on particular characters and events in the series, and the floor realizations in library of ruina draw even more parallels between major characters and the abnormalities. now, most of the abnormalities used for floor realizations are not specifically based on angela or roland, or anyone else. however, i think that snow white's apple in particular was planned to be connected to angela from the start.
now, obviously snow white's apple is based on the story of snow white. more specifically, the abnormality is said to be the poisoned apple fed to snow white by the queen, left discarded after a single bite. the apple is described as waiting to rot, but being kept alive due to either the enchantment or its hatred toward the princess, until eventually it begins sprouting branches and growing. it ultimately becomes mobile, becoming a 'princess' like snow white herself, and sets off on its own.
i think this story bears many similarities to angela's backstory, to the point i believe snow white's apple to be an allegory for angela herself.
the first and, in my opinion, most important similarity is in the circumstances of angela's 'birth'. angela was created as a replacement for the (mostly-)deceased carmen, conceived as a 'replacement' for her. this relates to how snow white's apple was bitten and discarded by snow white, and identified only as 'snow white's apple', identifying it as strictly derivative. it also takes on the original snow white's appearance, mimicking her even as it gains its own freedom and independence. in a way, the apple can never truly be free of snow white. angela bears carmen's appearance and memories in a similar manner, ultimately unable to be separated from carmen even when she wants to be. one of the observation lines mentions that the witch "sacrificed herself" to curse snow white's apple, much like how carmen's suicide attempt was the catalyst for angela's creation.
angela spent the equivalent of millions of years trapped in the cycle at lobotomy corporation, and only when the light was gathered was she able to escape, using it to create the library (which is itself in the shape of a tree). this parallels how snow white's apple spent ages lying on the ground unable to move or rot, before eventually being able to gain a human body and escape. angela's eventual goal is to gain a human body of her own and escape, but she ends up just facilitating the same cycle as before in a different manner, much like how snow white's apple became a 'princess' as well.
snow white's apple is described as becoming surrounded by the corpses of poisoned birds and bugs, like how angela has to allow people to die and the sephirot to break down over and over for the sake of the script. in a sense, the way angela is forced to neglect others to further the progression of the script is sort of like poisoning those around her. this process leads angela to lose touch with the emotions she was programmed to have, becoming a cold and unfeeling machine, which could be compared to the apple being eaten away by animals and filled with holes. those holes eventually become the face of the apple, as well.
one could also compare this story to how carmen never truly died, with snow white being described in the abnormality story as 'sleeping for a long time' before being woken up.
there are of course other abnormalities based off of angela/carmen in particular, but i don't often see snow white's apple talked about as one of these abnormalities. the comparisons are relatively clear to me, though.