Memorialized accounts are the accounts whose original holder has passed away but the friends or family have come together to share memories. Either you can choose a legacy contact to look after your account or you can have it permanently deleted. If the account is not permanently deleted and Facebook becomes aware of your passing, it will be memorialized.
A legacy contact of a memorialized account can change who can see and post tributes, delete tribute posts, change who can see posts that the original account holder is tagged in, remove tags of the original account holder, that someone else has posted.
Facebook on its official blog stated, “Tributes is a space on memorialized profiles where friends and family can post stories, commemorate a birthday, share memories and more. We’re working to bring this feature to everyone on Facebook, but you might not see it on all memorialized profiles yet”.
Posts made after the date an account is memorialized, are included in the tributes section. Facebook separates tribute posts from timeline posts based on the info they obtain.