Once inside the TARDIS, Spock was very interested to examine the mechanisms of the machine. However, to Spock's organized mind, the time and space traveling device was a jumbled mess. He quirked a brow, as he often did when he was concerned about the validity of a situation, and wondered if even Scotty (the crew proclaimed Miracle Worker) could even make out some semblance of sanity in all that wiring.
When the TARDIS jostled, Spock grew a little worried, though the emotion hardly showed on his face. McCoy might have noticed a quick glimmer of concern on the first officer's expression. But to the casual viewer he probably seemed unmoved by the situation.
Still, he grabbed onto a panel, in the event that the TARDIS moved in an unanticipated direction. Serving on the Enterprise taught Spock to be wary. At any moment one could go flying across the bridge.
Then they stopped. Spock peered out the door at the sunset. It was quite a lovely sight. But sunsets didn't evoke the same sort of feelings out of Vulcans as they did in other humanoids. Spock could appreciate the view, like he could appreciate a work of art. But from the outside it didn't look to have much of an effect on him.