Hi, Your question should really be, is Ubuntu really Debian? Well yes and no - I hate Canonical with a vengeance as much as I do M$ and tarty Apple.
Ubuntu uses the Debian package system. Zorin is a fork of Ubuntu, themed to look like Windows 7. It is not a hybrid like FerenOS which uses both Ubuntu and Mint repos. If it is to do with that screenshot, have you tried clicking on the bottom down arrow so you get to see Ubuntu?