I do not understand why the answer

lily88888UID: 2828533

helps to explain the disagreement

This is a question from Dec 1996

Of all the photographs taken of him at his wedding, there was one that John and his friends sharply disagreed about. His friends all said that this particular picture did not match resemble him, but John said that on the contrary it was the only photograph that did.

A: It was unique in showing John's face reflected in a mirror, the photographer having taken the photograph over John's shoulder.

duijinxiaoziUID: 2585955

关键词： unique
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John 天天照镜子，从镜子中看自己。
镜子里的影像，是左右颠倒的。John看习惯了。
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John的朋友没看过，John左右颠倒的样子，不习惯。

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图片中T恤上印的字是“"I Gotta Know"。
镜子中的字，是左右颠倒的。

duijinxiaoziUID: 2585955

再举个例子