MSP hosted I'm hosting the whole xml file for you and you host the media.
Blossom the xml file is on your blossom server which is satellite.earth in this case and MSP is just pointing to the current xml file on your blossom server.
Both ways you're still using S.E for the media and I'm just helping out. The only difference is where the xml file is located. Either my server or your S.E account.