For the photos to have value, they need to, clearly, show the wire going to both ends. Wires that go out of the photo and back in are impossible to, accurately, trace.
Show how the pot is now wired.
I wired a known good 1602 display to my WSP32 DevKit module and loaded the posted code with no changes. My display has a 1K fixed resistor from ground to pin 3 (Vo) of the LCD to provide good contrast. The display shows "circuitschools." on the top row and a 1HZ ish count incrementing on the bottom row.
So it is not the code, must be wiring or a bad display. Out of, maybe, 30 that I have obtained (Ebay and Amazon) 2 were DOA so it is not unheard of.