Blinking Off!

I was going throught the, Triggers tutorial, by Dave and followed the instructions for creating a Swap Set for Blink.

I created the Swap Set and added the Trigger, Blink Off and Blink On. I made Blink Off the default.

The Blink On was numbered 1 and then I tried it  and it worked great, but then it is suggested that 6 other layers are added to the Blink Off Trigger.

It seems to work without this step?

So, is it necessary to put the other layers into the Blink Off Trigger?