The subtle meaning of seemingly easy casual talk

The passage below is from Fathoms: The World in the Whale Hardcover by Rebecca Giggs.

She’s a marine scientist who worked for five years on the Nisshin Maru, on whales. Now she works with fish stocks — sardines and mackerel, mostly. Gesturing behind us, she refers to the Nisshin as ‘this ship’ (‘Now, could you have gone aboard this ship? No.’) —a small quirk of English, this ship here, or that ship there, that reminds me how subtly a language implies a perimeter of intimacy between object and speaker.

This passage is not difficult in its literal meaning, but I don’t think I know what it implies.

The problem starts at the part of parentheses.

(‘Now, could you have gone aboard this ship? No.’)

Literally, yes, no problem, but (Gee, What on earth is the purpose of this sentence?) implicitly nothing comes up to my mind.

So, neither can I get the implicit meaning of ‘a small quirk of English’, that is, why the sentence in brackets is a small quirk characteristic of English.

Nor can I ‘a perimeter of intimacy’.

(‘A perimeter of intimacy’ seems, though I’m not sure, to be ‘a degree of nearness.’ Am I right?)

Thanks in advance.