While "write a good feature" is a bit broad, it likely refers to one of two things: writing a feature request to improve this specific tool or understanding the existing "Featured"
This is the most likely reason you're seeing that URL. It allows you to keep a permanent backup of your posts, photos, and messages. Access it: Settings & Privacy Accounts Center Your Information and Permissions Request the File: Download or Transfer Information
Get-FileHash downloaded_file.zip -Algorithm SHA256