This looks rather nice and neatly displays an aspect of ant colonies that is hard to see otherwise. When done for research, I think that this is awesome. Have a look at the concrete pouring of a leafcutter ant colony (which is huge and has a very interesting layout) if you find this interesting: https://www.youtube.com/watch?v=lFg21x2sj-M

But then, having this memorial to an ant colony extinguished by hot molten metal sitting in my room strikes me as a bit macabre. At least intuitively, I don't even feel that sorry for the ant colony (which I think is the relevant organism eradicated here, not the individual ants), but turning its death into a work of art still feels tasteless. But then, I have ants as pets (I can only recommend to do that, it is not too much work but very interesting), so maybe I am overly sentimental here.