The JPEG itself is not physical, its storage is as is its reflection on a screen and these are two separate materialisations of the JPEG. If we assume it's the JPEG of a picture, it is the process of transforming a physical image into a physical storage of that image. The process itself is "non-physical"/mass-less (i.e. the algorithm), its realisation is physical (storage of instructions and execution).
The JPEG can be thought of as an informational abstraction. However, it is always instantiated on some physical medium and it can't exist independent of some sort of instantiation.
As for consciousness, it may not depend on brains, but it may turn out to always depend on some physical medium and physical process, and that would be enough to show that it's a physical phenomena.
This assumes not only materialisation but also objectification of consciousness. It could be that it is a process that mediates physical phenomena without itself being physical. A hole is not physical but it's realised in the midst of physicality.
The JPEG-as-analogy-for-consciousness assumes materialization of consciousness. Insofar as we're using JPEGs as a metaphor for consciousness, the fact that JPEGs can be regarded as an informational abstraction translated across different physical mediums is perfectly compatible with a physicalist story of how consciousness occurs, which was the point of this whole sub-thread.
>A hole is not physical but it's realized in the midst of physicality.
Yet no one seems to think this poses some metaphysical problem requiring us to go "beyond" physics to explain holes.
I may not understand your point correctly, but I would say yes, they do. The JPEG is an arrangement of atoms in an SSD. This is different from my experience of the color red that I see on the screen. The color red is physical. It is a type of photon with a tiny mass and volume. However my experience of it has no mass.
If you're willing to accept that a JPEG is an arrangement of atoms in an SSD then why isn't the experience of the color red an arrangement of neural impulses in the brain?
I don't agree with the person you are replying to at all. But I can still respect their point that there's a distinction to be made (or at least argued for) that the kinds of explanations we give for JPEGs are ultimately physicalist explanations. Everything on your list is a different physical medium a JPEG could be realized on (though maybe some would debate the last one).
But the person you are replying to probably wants to argue that qualitative experiences aren't realized on any physical sort of anything, let alone translatable across various physical mediums.
Now, again, I think that argument is wrong- I think these experiences happen in our brain, though it's currently unclear exactly how - but I at least understand their impulse to put those experiences in a different category than a JPEG, and why the ability to translate a JPEG across different mediums wouldn't speak to the concern they are raising.
Well, technically photons are massless and don't have "volume" in the common sense of that word. Red photons do have a particular energy, but I don't think any photons in the real world have exactly the amount of energy that a theoretical "red photon" is defined to have.
The JPEG is not a JPEG until it's processed by a program. Until then, it's just an arrangement of bits. Likewise, light has no color until it's absorbed by your retina and processed by your brain. Until then, it's just a photon of a certain wavelength.