Before we get started, I’d like to note that this is just some fun speculation and not a “smoking gun” type of image. The correct explanation is usually the most obvious.
A promotional video from 7 Net Shopping has been discovered which advertises a steel case pre-order bonus for Pokémon Let’s Go! Pikachu and Let’s Go! Eevee. Fans have quickly noted that the art featuring Eevee is slightly strange, in that mysterious dark crystals appear as a representation of one of its evolutions. With no clear portrayals of ice, it’s logical to assume they may represent Glaceon. That being said, why would Glaceon be represented by black ice?!
There is another argument that Glaceon’s homage may be found in the dark energy in the right-hand corner, or even in the white space of the lightning above Eevee. This would mean that the black at the bottom represents an entirely new and unrevealed Eevee-lution!
We’re mostly putting this up for conversation, because, well there’s a lot of room for discussion! Take a look at the image I made that lays out the types and the video itself, then let us know your opinion! Here at PokéJungle we recommend fans temper their expectations and assume it is simply black ice representing Glaceon for now.