Is the Japanese version glossy? This card seems to be extremely hard to find
Please don't bump a two year old thread just to ask a question. Next time just create a new thread in the Just A Question? section and link to this thread.
To answer your question though: no, it's not glossy. The difference is the cardstock used. The ones from the Japanese VHS are printed on Japanese cardboard, which is slightly thinner than the US/International cardstock. If you have both cards in hand and shine through both of them with a flashlight you will clearly see the difference.
The same applies to the Shadowless Base Set yellow Cheeks Pikachu, which was also printed on Japanese cardstock in the Pokémon Song Best Collection CD. As you can see in the pictures, the Japanese one is also slightly lighter in color, which also applies to the Pikachu.
Just looking at auction pictures you will most likely not see a difference. The only way to know for sure is find one of these sealed VHS with the Mewtwo still in it.