It sounds to me like you want Desktop Mirroring to be 'on' so that the tv and the computer screen are the same desktop. As it is now, it sounds like your computer is treating the tv as a second desktop, which perhaps is not what you want.
Somewhere in your System Settings > Displays you should see something to make both screens be the same thing. It's hard to tell you exactly where, because it will differ depending on what Desktop Environment you use.
Example from a KDE session: