Of course, none of this is actual footage from the show. It was all staged purely as an enigmatic promo, like when the castaways from Lost all slow-danced and groped each other as if they'd just discovered a Dharma Initiative bunker full of ecstasy. Still fans are intent on searching for clues, first in the statues themselves. Notably, Sansa and Arya's stone likenesses look approximately the same age as they are now, while Jon's looks much older.
This could imply that Jon survives into old age, while his sisters bite the dust early. Also, Jon's statue seems to have one eye closed, perhaps suggesting he'll lose it in battle, or that the show will end with him winking directly at the camera. Then there's the feather that floats to the ground as Jon passes. Dedicated fans recognized this as the feather Robert Baratheon placed on Lyanna Stark's tomb way back in the first episode, and not, say, a shout-out to Forrest Gump. Some have interpreted this as foreshadowing that Jon will soon learn that Lyanna is actually his mom -- and on the ickier side of things, that his new girlfriend is his aunt.