Exactly. Apple does not refer to this icon as the 'share' icon in official documentation. It is actually the 'action' button[1]. As in, I have some data in this

Exactly. Apple does not refer to this icon as the 'share' icon in official documentation. It is actually the 'action' button[1]. As in, I have some data in this app, and I want to do something with it outside of this app. Hence, the symbol of an arrow moving outside of something. Many of the possible actions resulting from tapping that icon (on iOS) may be unrelated social sharing (e.g., copy, save to photo library, assign to contact, etc.). [1]: UIBarButtonSystemItemAction; https://developer.apple.com/library/ios/documentation/uikit/reference/UIBarButtonItem_Class/Reference/Reference.html#//apple_ref/doc/c_ref/UIBarButtonSystemItem https://developer.apple.com/library/ios/documentation/uikit/...