> M looked at his wristwatch from any direction to check the time

In my understanding the meaning is « M can check the time from any direction ». As you and me of course, but usually our spacial memory retrieve the time from the needles orientation (no digit watch in WW2) so we use to always check the time in the same position (12 upward). As M can’t rely on the position of what he see, he probably just « read » the watch numbers all the times (no pun).