Yes, you can but these are two different functions. You can mute the screen by using the remote or the buttons on the front, bottom, right corner.
You can freeze the current screen displayed on your Classic by swiping up from the bottom left or right corner.
This will bring up a menu with a snowflake icon. Press this icon for your screen to freeze.
The display screen remote has a 'Freeze' button and on a pulse remote the freeze is the blue button.