I would press it with your finger and wait until the LCD updates, to see if that produces better image. If so, it means the little rubber thing between the LCD glass and the PCB is not making great contact. The Nokia 5110s are pretty notorious on this issue. Maybe MHat R4 will use the other OLED which I personally like a lot better (its just not as low power as 5110, not that it really matters in most projects).