What is the definition of Grows Fluid?

"A 'grows fluid' is like a sentient, ever-changing kaleidoscope of emotions, constantly shifting between sunshine and rainbows—or maybe just a really bad mood swing. But let's dial it down a notch with an unsettling example: 'After the boss yelled at me about my terrible presentation, my stress levels grew fluid like molasses, turning into a thick, gooey, and utterly terrifying sludge.'"