It's not being used to play golf. Eyeglasses, a 9-volt battery, and a sharpie are also "unusual equipment for golf…" except for the fact that they're a special category of equipment called "artificial devices."
What are eyeglasses and a laser pen (etc.)? Artificial devices. Just like a book, or a calculator. You can use a calculator during a round of golf, and use it to calculate things, but you can't hit your ball with it.
I will not take a stand here as the issue is rather complicated but I just throw in some questions:
What is it that constitutes 'an unusual equipment'? Is it unusual for golf or unusual in general? As we are dealing with Rules of Golf I would go for the former.
Following preceding logic, IMO a laser pointer is certainly not an usual equipment for golf, unlike eyeglasses, 9V battery, (Rules) book or binoculars. Can we thus say that it is an unusual equipment? Well, I would say so.
Next question is: when an unusual equipment is allowed? Well, that is a good question and the allround (arbitrary) answer is given in R14-3 as already indicated. So the answer should be found from there but against all odds that Rule is not very specific.. ;-)