This is the screen that will welcome you to the desktop, if you would like it NOT to show when you start your machine just uncheck the box at the bottom left of the window and it will not show on your next boot. It will still be available through right clicking on the desktop, select run command, and type welcome-screen.exu in the dialog box.
From here you can
1.) run the desktop profiler (in case you thought you would want minimal but realise there are not many packages installed and decide to install the full desktop)
2.) run the software centre to install other pre-packaged applications (like Skype, Teamviewer, Dropbox to name a few)
3.) Install Proprietary Codecs, these will allow the best experience of most modern codecs available.
4.) Turn on desktop effects, this will give you more "bells and whistles", just remember everything you turn on uses resources and if you are using a lower spec machine it may slow up a little.
5.) Switch the "start menu" to the "kicker menu", selecting this will toggle between q4os menu and the kicker menu.
6.) Set autologin, this will toggle on / off the autologin feature