Do note that on the server it will download Lion including the server app. One way to tell that is that the image is larger in size than Lion downloaded for an ordinary Mac via the App Store for the same version of Mac OS X.
If you want an installer for Lion without the server app you'll need e.g. a 2011 Mac Mini (non-server) or 2011 MacBook Air to get the download. Late 2011 MBP may also work.