Review the sentence:
Inserted in the group text reply, Charlotte included another selfie with
eerie red eyes.
Inserted in the group text reply, a participle phrase, is describing Charlotte when its target should be selfie. When a modifier is next to a word it doesn't logically describe, it is misplaced.
To fix the problem, you could revise the sentence like this: When Charlotte replied to the group text, she inserted another selfie with eerie red eyes.