I have to agree with psnorthrup. The code does not dictate what can or cannot be plugged into the laundry circuit.

Joe, CMP-2 would probably disagree with you in theory. After all, it's the intent of the code that matters:

"Panel Statement: The intent of this section is to require at least one 20-ampere branch-circuit that is dedicated to the laundry area to ensure that the branch circuit is sufficiently sized to supply electrical equipment associated with doing laundry, such as an iron."

Is an irrigation timer associated with doing laundry? I think not.

Humm.
Looking at the two small appliance circuits required you will see similar wording.
So if I set the timer in the kitchen and plug in the power pack to a outlet?
Or for that matter my phone charger,Tom Tom, Laptop,Tv,etc. Which has nothing to do with food prep?

Humm????

I don't believe the original question - was about plugging in portable devices, or a radio, or a night-lite, or a phone charger.

One can cloud the issue 1000 different ways, but the intent of the code is clear and remains the same.