Well, that isn't chainmail, unless they're taking some artistic license with it's representation. Chainmail is essentially a number of metal rings woven together, it depends on the gauge of the metal and the type of weave, but a typical European 4-1 weave is largely flexible like cloth and could tear that way depending on how fine the weave is. Getting ridiculously into the realm of speculation, since we're talking about magical armor here it theoretically has a very fine weave while being stronger than anything that fine has any right to be, in which case it would tear *just* like cloth. Assuming you hit it with enough force to tear it in the first place.
Below is a photo of a banner I made for Mythic Entertainment. It's about 4'X6' as I recall. It's flexible enough to be rolled up like a carpet, or worn as a superhero cape, blanket-style like we did when we were kids.