I don't see how tears from crying over different types of feelings could actually be different. Maybe the onions one because the vapors get in your eyes. The rest seems like bullshit.
So it looks like the pictures differ more from just how the liquid dries and the microscope settings- the article even says that two images of tears of the exact same chemical structure will look very different
What do tears of "I hate my job, but I'll never get out of here because what I do is so specialized, and I am not qualified to do anything else" look like?
*cries uncontrollably*