I must admit that the pizza of Ale88 is a piece of art. I didn't even know the existence of purple cauliflower

Yes it exists, in Italy it is a very well-known and consumed variety of cauliflower, the taste is honestly the same as the others, it just has a different and beautiful appearance to look at. I agree with you though, his pizza is really very artistic, it looks like a painting by Michelangelo Buonarroti

I agree that the Ale88 pizza is quite artful and detailed, yet my main question remains whether OP had actually cooked the pizza and provided a picture in cooked status since the art may well not maintain itself within a cooked status, yet at the same time, having the pre-cooked art in a pristine artful look would still have some value even there would be changes upon cooking. Maybe I am missing something since it seems to me that none of the pictures look cooked.. because the cheese and some of the other parts of the pizza shouldnt be able to stay with such details upon cooking.. so then repeatably, aren't the contestants supposed to submitting cooked version of their pizza? Or is that just a question that relates back to how much weight does the pizza get in terms of actual votes, since non-edible pizzas would likely receive fewer vots.. and surely Op had proclaimed that the artful pizza had been eatable..yet at the same time seeming to having had been accomplished with a lot of good carving skills from little hands, difficult to imagine from some of us mere clumsy mortals...
This is actually a good question! Well done!
In fact, from the photos it might seem that it is not cooked but if you look carefully, the frame or edge (depends on what you like to call it) of the pizza is obviously cooked.
In Italy, certain foods for pizza do not need to be cooked, such as Parma ham, bresaola or rocket, just to give examples. maybe Ale88 cooked the condiments such as sauces separately to preserve the appearance and taste. And maybe even the cheeses were added after the pizza was cooked! There are some pizzas where the pizza base with the tomato sauce are cooked separately from the toppings, maybe OP replicated this method
These are obviously my suppositions and only Ale88 could confirm or deny what I said! Maybe he himself will explain to us the method he used.