From the name of it, certainly it looks for posts with the highest scores. However, recently I found that some of the posts are not listed.
Example: My answer on UX.SE (not sure if it's that good, just because hot network question) was included in some point, but then it's not listed on my profile. I guess it's because the question was closed, e.g as a dupe? (I don't have any hidden communities on the settings)
However, it's listed normally on Stack Exchange profile for top posts.
Also, what other criteria that makes the posts to be included/excluded in "Top network posts"?