I asked a similar question here:
What is 剋 doing in the Cantonese translation of the movie title “Widows”?
The Cantonese title of the film Us has been translated as:
香港譯《我們·異》
Wikipedia also mentions that:
中國大陸、台灣譯《我們》
So, it seems that the Cantonese title is quite different here.
Guangzhouhua-Putonghua only mentions Mandarin definitions.
While Words.HK only gives the following:
語素
1
有分別;同其他嘢唔一樣
different異口同聲
ji6 hau2 tung4 sing1
saying something together; literally, different mouths but same voice差異
caa1 ji6
difference2
唔正常嘅
unusual; extraordinary異味
ji6 mei6
peculiar smell異常
ji6 soeng4
abnormal
I'm still not getting the pun, though.
Any ideas?