Jajaba,
This is incorrect. Energy released into photons from your display is _not_ heat dissipated in your Macbook. Some of it may be absorbed in your retina, at which point some of the energy is transferred to heat in your eye, some of that photon energy is transferred electro-chemically into your nerve cells, some of it is going to be reflected off of your cornea. Other photons released by the CFL in your macbook will travel elsewhere and may get absorbed or eventually add to the cosmic radiation background if they manage to leave the earth's atmosphere. But they are _not_ going to be transformed to heat inside your macbook (heat, in the case of a solid object, can be represented as phonons, essentially quantum heat particles, just as photons are quantum particles of elecgtromagnetic energy, but phonon does not equal photon, thus the two distinct terms).
So, to recap: Not all energy is heat, though, by the second law of thermodynamics, the tendency of a system is to increase its amount of heat energy if work is done within the system. Yes, some of the energy released by CFLs is in the form of heat, but some of it comes out of the display as light - where else do you think the energy for the photons emanating from the display comes from? The photonic energy may eventually be turned into heat, but once the light has left the laptop, that heat will not contribute to the temperature of your laptop.
How much of the energy used by the display ends up in heat depends on its efficiency. That is why LED light sources are the preferred option, since they generate more light per amount of energy used (and thus less heat).
As for your thought experiment: You could envision a box inside of which you mount some photo-voltaic cells that capture photons emitted by that CFL. You can charge a battery with the electricity generated by those cells, thus storing energy chemically. Clearly, that energy will not have gone into heat (that is, until the battery is fully charged and can no longer accept input power).
Now, the energy released as light from your display may admittedly be a fairly small amount of the overall energy budget of a laptop, and virtually all of the energy consumed by most of the electronics inside the laptop (such as the CPU and SDD) _will_ get released as heat. But if I recall correctly, the question was about the light source in the display, which is specifically designed _not_ to release all of the consumed power as heat.