I think you all have missed the boat. The fact that it lists:
Metroid Prime 2 Echoes
and then below it
Demo Disk(in yellow) is awful suspicious. It's vague marketing. Some people will read that and think both are full titles. If they wanted to be honest, they would have said demo disk in white right next to Metroid Prime 2. It's perfectly legal and totally sneaky.
Ask yourself, why is 'demo disk' highlighted and not 'Metroid Prime 2'? Sneaky sneaky sneaky, makes you thinky theres a bonus disk and MP2.