I get the point and see I might connect two different points. Just asking you to turn the situation around: Imagine you had no contact for several months. No pictures or anything changed. Then your ex asked you to send her stuff. In response, you change your message pic into one with your new girl and text your ex, hey sorry did't have time to send your stuff. I go for holidays today.
How would you make your ex feel about this? intended or not fully intended from you.
I'm really not trying to refute you outright here; the circumstances and timing are definitely hurtful for you, and her intentions don't really matter if you're actually hurt by this.
But do you really think that she changed her profile picture "in response" to you asking for your stuff back? I'm not saying that she did or didn't - and the timing is maybe suspicious, and maybe she IS sending you a message with the profile picture change. But she might not be. I think there is plenty of reasonable doubt there.
