Do you mean they haven't put launcher icons on your desktop? Are they both in the app drawer?
I'm not that familiar with Samsung's Touchwiz launcher, but with most launchers you can press and hold the point on the desktop you want the icon to be, then select "apps" from the list of options and choose the app you want to add.
There's an option in your Play Store settings to choose whether you automatically add icons to the desktop when you install a new app. I thought they left it on by default (I personally always turn it off, but people's preferences differ).