請問一個對話聽不太懂 - 六人行

Season 1的第四集，有一段對話，我是照英文字幕的打的，但是我聽不太懂什麼是
Mr. "The glass is half empty."

Ross: So, I'm guessing you had an extra ticket and couldn't decide which one
of you got to bring a date?

Chandler: Well, aren't we Mr. "The glass is half empty."

這個是什麼意思呢

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