cut of one's jib

今日も単語ではなく慣用句を採り上げます。その慣用句は "Evil Under the Sun" で探偵ポアロと同じホテルに滞在している客との次ぎの会話にありました。
Poirot asked: "And why should you suppose the contrary?"
Mr. Blatt closed one eye. He said: "I'm a man of the world. I know the cut of a fellow's jib. A man like you would be at Deauvelle or Le Touquet or down at Juan les Pins.
"cut of a fellow's jib" はどんな意味でしょうか？
・Dictionary.com: one's general appearance, mien, or manner: I could tell by the cut of his jib that he wasn't the kind of person I'd want to deal with.
・Wiktionary: (idiomatic) A person's general appearance, manner, or style.
"cut of one's jib" がどうしてこの様な意味になるのか不思議ですが、どの辞書にも由来は書かれていません。しかし、何度か利用した事のあるThe Phrase Finderに説明がありました。少し長くなりますが、次ぎに引用します。
The jib of a sailing ship is a triangular sail set between the foretopmast head and the jib boom. Some ships had more than one jib sail. Each country had its own style of sail and so the nationality of a sailing ship, and a sailor's consequent opinion of it, could be determined from the jib.
The phrase became used in an idiomatic way during the 19th century. Sir Walter Scott used to it in St. Ronan's Well, 1824: "If she disliked what the sailor calls the cut of their jib."
There may be an allusion between the triangular shape of noses and jibs in the figurative use of this phrase, but this isn't authenticated.