It is an exemplary way of suggesting that search engines can be more fun than they already are. Time and again Google has amazed every one of us with degree of effort they put into innovation. Be it Chrome, their doodles or searches which amuse you for a few second.
Latest such gimmick is Easter egg ‘Do a Barrel Roll’. If you type ‘Do a Barrel Roll’ on Google, you will be entertained for 5 seconds and its memory might stay with you longer than 5 seconds. If you search for ‘tilt’ the screen gets tilted. Searching for ‘askew’ does the same. If you write ‘Z or R twice’, it produces the same effect as ‘Do a Barrel Roll’.This Barrel Roll is tribute to 1997 Nintendo game Star Fox 64.The move to deflect shots from enemies was executed by pressing Z or R twice on the controller and hence the ‘Z or R twice’ alludes to the same and does the trick to amuse you for a few seconds. This gets executed whether you search web or images.
These features are best supported by Firefox and Chrome browsers. They showcase the powerful new feature CSS3 of advanced browsers.