Just because you can doesn't mean you should.
I'm always looking for new ways to cook fish. To clarify, when I say "new ways," I generally mean a new recipe.
Then there's this:
So that's new...
It does make sense to cook a fish in glass. The fact the juices don't escape and makes for a nice, moist filet sounds very interesting and appetizing. If nothing else, it would be fun to watch someone do this regularly.
It probably goes without saying, but don't try this at home. If you do want to try this out, your best bet is to head to Gotland, Sweden.