Prior to the new “floating” command line, if you wanted to see more or fewer lines on the command line, you could simple drag the edge of the command line up or down (as shown below – and if your command line is “docked” it will behave the same way with 2013 or newer versions…
But if you try the same thing with the new “Floating” command line, it will obscure your your drawing area. So what you may want to do is increase or decrease the amount of command line history that is shown but then fades away.
To do this, click on the “wrench” on the command line and then select “Lines of Prompt History.” This will launch the command/variable CLIPROMPTLINES. The default value is 3. Change to the desired number.