I vividly remember the sense of dread the original sequence gave me when I first saw it.

The rebel's escape is not assured as fighters pursue the Falcon. Vader has been thwarted on Bespin so what is HIS next move? The order to bring his shuttle does not fully reveal his intentions but they do have intent mixed with frustration and annoyance. He has something up his sleeve.

The sight of the Executor blocking the Falcon's flight from the Cloud City heralds the might of the Empire finally bearing down on our heroes like a cruel wedge of inevitabity. Vader's sudden appearance on the bridge of the Star Destroyer really compounds the sense of hopelessness and shows Vader personifying the seeming omnipresence of the enemy. There is no escape.

Did you notice that I didn't feel the need to point out "This was the moment I realised what Bring my shuttle meant and where that shuttle was going to take Vader and whether or not the Star Destroyer was actually prepared for him arriving."?

The reason for this is that is so utterly self evident in the scene of Vader's arrival on the bridge that The Empire have been prepared for this turn of events since before the rebels even arrived in Cloud City. Vader's plan to personally acquire Skywalker through persuasion has failed. He is now falling back on the less satisfying plan B of capturing the sabotaged rebel vessel. The frustration in Vader's curt command shows his displeasure at resorting to a crude entrapment using the largest Imperial vessel at his disposal.

It's telling that he seems unmoved, thoughtful even, when the Falcon vanishes into hyperspace. He's failed already. Perhaps he's pondering the ability of a tiny band of rebels to defy the Empire.