Well the first picture was just leaks from a pipe that was running above that corner. Who knows how long the leak had been active.
I’ll attach some images of the pipe that was running above the corner. You’ll notice the red area(plumbing pipe) running along the ceiling and into the corner, then the blue moisture areas going down the wall.
I always cut all the water in the house on at once and let warm(not hot, so I don’t run out) water run for about 10 mins. Then I do all my Infrared scans so I can see where the plumbing pipes are and if any are leaking. I also mark any drain lines that stand the chance of being punctured from hanging a new flat-screen TV with blue painters tape.
On the 2nd image, it had rained about 6-7 days before the inspection. The ground outside was dry but at a negative slope so the area was obviously adsorbing a good bit of moisture.