The note bellow of yours contain an image hosted on a blossom server. If that server was to go down, your peers clients could ask all the blossom servers it knows for the same file. That's why it is nice to setup multiple blossom destibations in your client. You can manage your blossom list using clients like amtehyst and others like bouquet allow you to manage your blossom media and ensure redundancy.
Hope it helps!