It's the second hand for a chronograph… aka a stopwatch. That's why it's at 0 seconds in both pics — the chronograph isn't in use.
>>5469006 is an excellent resource.
For those who are still wondering about how this watch works.
First, hats off to anon who created graphics in >>5469006, which are a good visual. And I agree, it's 3:41:53. (I am open to being convinced that 3:42 is important because rounding, but I don't think Q works that way. I think seconds matter… just like how he is always trying to hit the 0 delta.)
For those who are still skeptical of the chronograph vs second hand feature, here is a video of the watch (or a very similar one) in action.
Right off the bat you can see the second hand in action in the bottom dial while the long hand (what would normally be the second hand on a regular watch, but is the chronograph second hand on this watch) is stopped at 0.