Only people who manage your Page can see who published a post
ex: Yor page with 2 or more admins, that shows who posted that post
(posted by visible only to admins not to visitors or liked peoples)
If another one clicked on your post they seen as that page posted
and when you’re going to post inside that box posting icon is there the change if you want to post add you or that page.
It Is a Bug, We Noticed in Facebook while using it on Google Chrome Android Browser. We are Scrolling to Load News Feed of Facebook but In Middle of News Feed We May See Several Sponsored Ads to Like Pages, In This Case Facebook Auto Likes Sponsored Pages from Users Profile while They Hover the News Feed or Sponsored Ad.
So, By This Facebook can Estimate a Post Reach for Advertiser Who Advertise Using Facebook.