- `InstaloaderContext.get_page_data()` loads a page as a logged-out visitor and returns the query results that the page embeds. Instagram only embeds them when the request looks like a page navigation, so the request sends the `Sec-Fetch-*` headers of one.
- `Profile.from_username()` reads the profile from its public page. Anonymously, `_normalize_profile_data()` completes the node.
- Logged in, `Profile.get_posts()` uses query `28975909992013618` (`PolarisProfilePostsTabContentQuery_connection`) with the variables that the web app sends. The response has the same shape as before.
When logged in, `from_username()` does not normalize the page's node. The page shows the profile to a logged-out visitor, so normalizing would set `followed_by_viewer` to `False`, and `download_profiles()` would refuse private profiles that the session follows. Instead, the GraphQL profile query in `_obtain_metadata()` fills in the missing fields when they are first read.
Fix Profile.from_id(), Profile.from_username() and Profile._obtain_metadata() by using `users/web_profile_info/` and `users/{profile_id}/info` queries.
Markus Magnuson