This BW Promo card, that was originally meant for the 2011 World Championships qualifier prize (according to Bulbapedia), is one of the few cards that never got to release due to the 2011 Tōhoku earthquake in Japan.
Update 22-03-2021: Physical copies of these lost BW promo's have surfaced online. From what we have been told by our friend in Japan, his friend asked TPC if there was any way that this card was distributed in the past. TPC said that they have never distributed this card to anyone. So these promo cards might be obtained unofficially.
GrollenKette951 was searching for this card today in the Japanese Pokemon-Card.com database and found it. Up until this day, nobody outside of Pokémon knew what this card looked like and what kind of card it was. It was really a 'Lost Card' for over 9 years.
The other never released BW promo's (025/BW-P to 031/BW-P) that were meant for this tournament were already known before, only 027/BW-P was missing for many years and was never revealed.
Unknown if any real life copies exist or not, physical cards of these lost BW promo's will likely never surface, they could have been destroyed. Time will tell.
Here it is in all its glory.
Thank you very much GrollenKette951 for informing us of this discovery!