Most planets form in a disk of gas and dust that rotates in the same direction as the young star at its center. The material in the disk, the star, and the planets that condense from it all share that initial spin. A planet orbiting in the opposite direction therefore stands out immediately.
The exoplanet highlighted in the report does exactly that, circling its star in a retrograde orbit. The source does not explain how the planet ended up this way, and it does not provide details about the planet's size or distance from its star. Even without those specifics, the finding is notable because it shows a planetary system that does not match the usual formation picture.