The three polarizing filter experiment using common sources of light can be explained perfectly without using quantum mechanics [0]. These effects only need QM to explain in the single photon regime. The polarized light from the LED display is definitely not in the single photon regime thus this experiment does not demonstrate any quantum effects. Without any quantum effects, it is much more difficult to justify the quantumness of this supposed quantum computer.

[0] http://alienryderflex.com/polarizer/