I believe it's a reference to Full Metal Alchemist, where one of the key principles of their magic system was 'you get out what you put in', ie 'you put two units of iron and one unit of carbon in shape A, you get two iron and one carbon in shape B' (although you could do anything from 'make a steel alloy' to 'I want these things separated into teddy bear shaped ingots') . Here it looks like a primarily metal object is being turned into something with some metal and a larger amount of non-metal, so the law isn't being obeyed here.
...unless that was a rhetorical question or something.