My guess is that clay goes through a transformation at about 800 degrees F to what is called metasilicate that is very porous (a lot of Mexican pottery is that way which is not a bad thing. In the desert, as the water bleeds through it and evaporates cooling the whole thing, so a vessel left out on a porch will be a lot cooler than another vessel that did not do that. However, if there are freezing temperatures the water becomes ice, expands, and the clay breaks as you often see that texture on brick buildings where the water sinks in a little and the surface pops off.
As the material heats more and more the pores shrink until they become bubbles and can even pop leaving a pitted surface, but as the heating continues it becomes a glassy surface as you see on the top.
As you get farther and farther away from the laser hit the process proceeds less and less till it is not even metasilicate and will soften and dissolve in water, that part is to me the most interesting as it could be done in a design that would have openings and so a screen like look,
A special formula would get you silicon carbide that conducts electricity with some resistance (not very much) but the longer and thinner it would be will get (i think) a solid heating element with many possibilities including much higher temperatures than nichrome. and the possibilities of a Hilbert Curve or here and where I chimed in make some awesome possibilities though kinky places are hotter than those that are not which can create problems but less at low heat than high heat.