What is the meaning of Al-Ghazzali's following allegory? Leave comments

"Once upon a time the Chinese having challenged the Greeks to a trial of skill in painting, the Sultan summoned them both into edifices built for the purpose directly facing each other, and commanded them to show proof of their art. The painters of the two nations immediately applied themselves with diligence to their work. The Chinese sought and obtained of the king every day a great quantity of colours, but the Greeks not the least particle. Both worked in profound silence, until the Chinese with a clangor of cymbals and of trumpets, announced the end of their labours. Immediately the king, with his courtiers, hastened to their temple, and there stood amazed at the wonderful splendour of the Chinese painting and the exquisite beauty of the colours. But meanwhile the Greeks, who had not sought to adorn the walls with paints, but laboured rather to erase every colour, drew aside the veil which concealed their work. Then, wonderful to tell, the manifold variety of the Chinese colours was seen still more delicately and beautifully reflected from the walls of the Grecian temple, as it stood illuminated by the rays of the midday sun."