The first thing I think of when I hear 'calamari' is the often-expressed opinion that it is like eating 'fishy rubber' and when I read this question I immediately had a vision of someone with rubbery, flabby lips (yuk!) - to me, the words speak of consistency rather than shape . . .
However, calamari is most often served cut into rings - like a gaping O, so it could also be a description of someone whose mouth is permanently hanging open . .

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Note added at 13 hrs (2006-05-09 00:25:36 GMT)
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Although maybe not the O shape. since she's watching them moving . . .