This clip is the culmination of a large pod’s planned and well thought out hunt of that seal.
They would pop up vertically all around the iceberg to visually inspect the surface conditions and pinpoint the location of the seal on the iceberg.
The pod stationed members on either side to keep the seal stationary, staged a few behind the berg to wait for the rest of the orcas to charge the iceberg head on, then dive under at the last moment to send the wave over the top, washing the helpless seal into the waiting jaws on the far side.
Orcas are magnificent animals, so smart and cagey, kinda spooky even but I just love how deadly they are. The ocean terrifies me for multiple reasons but I can respect a predator this cunning.