>Literally the last second of 4:49
This is incorrect. The correct answer is: The watch is a chronograph, the large second hand on the face is used for the stop-watch function of the device. The true 'second hand' of the clock-portion is the small circle above the 6-o'clock position. The time on the watch is in fact 4:49:30.
No problem. Seems like it's a pretty nice watch.
https://www.iwc.com/en/watch-collections/portugieser/iw390302-portugieser-chronograph-classic.html
>Q+ set the Marker [1] to the literal second.
Certainly possible, though I think Q has said in the past that for post/tweet deltas the seconds are irrelevant because of too many outside factors that could influence when a post actually goes through and is recorded. That was because of how the internet and websites are structured, though, a physical object you have immediate control over might be different so the seconds could very well matter. Depends on if the post/tweet rules apply to the times on the watch photos as well.