Very nice.. so friendica can be used directly from my browser
This addon basically redirects you to your profile page, and submits data from the page you were previously on*, into the post box. It's not an automatic and smooth experience, but then again this gives you more power to edit things in the post, and select who should see it. Edit: would be even better if it implemented a toolbar button.
*a title that links to the page you shared, and below that a page description