It's a question of how the eye and the brain work.
這個問題有關眼睛和大腦的工作原理。
Different areas of the eye are responsible for picking up different information about light and dark, colors, background and foreground.
眼睛的不同區域負責獲取關于明暗、顏色、背景和前景的不同信息。
The information takes different channels through the brain.
信息通過大腦的不同渠道傳遞。
Luiz Martinez Otero, a Spanish scientist, said in an interview,
西班牙科學家路易斯馬丁內斯奧特羅在接受采訪時表示,
“Sometimes one channel wins over the other, and you see the smile.
“有時這個渠道勝過了其他,你就看到是笑的。
Sometimes others take over, and you don't see the smile.”
有時其他渠道占了上風,你就看不到笑容。”