[fermienrico]

Also, if we go a little deeper, then intensity is really not intrinsic property of photons themselves. Photons radiate through space and are carriers of electromagnetic force. They have momentum but no mass. Its energy and momentum is a function of frequency (or wavelength). Furthermore, they also have spin angular momentum which is truly intrinsic as it does not depend on frequency.

So, the saying that light is just "intensity and frequency" is naive and flat-out incorrect.

[coder543]

It isn't possible to make light that is faster or slower than other light, so does it matter that some other property is derived from this constant* ? A property derived from one variable and a constant property is perfectly logical to refer to as intrinsic, since it's always exactly linked to one intrinsic property. Splitting hairs there doesn't make sense.

Which things can a light source vary, besides wavelength and intensity? It's easy to define intensity in this context as the photons being emitted per period of time. This isn't like trying to define the intensity of sound as an intrinsic property, when it really depends on a number of actually intrinsic variables.

*within a given medium, which is external to the light... which means it won't change based on reflected vs LCD.