They were showing it for all the first weeks after ANS died, on ET or another, showing it covered over with plywood, but already dug, as if for ANS.
Now I'm thinking that was possibly Daniel's (although the one next to this one has brown grass and the others don't, because it's new sod squares, just put back on top after burial)? No, they wouldn't open it up with him in it, even tho they've been saying she will be buried on top of his, would they?
Maybe there's something down in the ground that's on top of the coffin that's already in there, for when they open it up to put a second coffin in it - like some kind of platform.

John Negri of Altoona, Pennsylvania, photographs his wife and daughters at the gravesite location believed to be of Anna Nicole Smith's son Daniel, at Lakeview Memorial Gardens in Nassau, Bahamas February 25, 2007. The Negris were visiting the island for the day off a cruise ship and took a cab to visit the cemetary and ocean-front home of the late entertainment celebrity claiming the spots were the 'talk of the ship'. REUTERS/Hans Deryk (UNITED STATES)
usually when they double stack them the use a concrete vault around each casket. They dig deep enough so that 2 of these concrete vaults can be stacked on top of each other.
Part of the reason they use the concrete vaults is due to the ground sinking in when you don't use one. Eventually a casket will rust or rot away if dirt is the only thing that is around it, then the soil will sink in as the coffin gives away from age. (I not into being buried in the ground - I will be cremated because I think it gross to be put in a coffin and then put into the ground - the opposite of what Anna felt - she thought cremation was gross.)