Hello,
Whenever I share my shopify site link through iMessage, the thumbnail is the default (circle compass). How do I go about altering this? Any help would be appreciated! Thank you.
Hello @PorzakGolf 
You can read this article to learn how to change social media share image
https://help.shopify.com/en/manual/online-store/images/showing-social-media-thumbnail-images
Hope that helps!