Claudio,
I want to set the desktop property to true because of the sizes of the forms. Form 2 is larger then Form 1. Being Form 2 is in top level it is inside of Form 1. This prevents you from seeing all of it. Setting the desktop property to true on Form 2 allows it to to be displayed anywhere in the windows desktop area independent of Form 1.
As far as your example goes that's how my forms are setup.