Maybe that wasn't CGI, but real sets being built. I think "under construction" is the theme of the whole thing. Beyond that, I really doubt Abrams really cares what's read into it (well, he wants us to like it, which seems to be the case). As I posted above, I'm beginning to believe those workers were meant to look 1960ish. The only thing missing was somebody's lunch box sitting on the saucer. I mean, even today most precision welding is done by robots. And you have phasers, but still weld in the 20th century manner? If that's supposed to be an authentic representation of the building of the Enterprise, then I want to see a Federation inspector going around to test all those welds. From the point of view of saying it's something new YET it's still mindful of the optimism and promise of space exploration that fueled TOS in the 1960s, it's damn good.