What does "gentle interrogative" mean?

Question

While browsing Jishio.org, I come across this definition of こと. I tried googling "gentle interrogative Japanese", and found not much that explains what differentiates a "gentle interrogative" from another interrogative.

I then tried searching several times on Japanese.stackexchange.com, but nothing came up that aids my understanding of what a "gentle interrogative" is, what it means, and what makes it 'gentle' in comparison to other Japanese interrogatives.

Edit: Well then, I have no clue how to interpret the こと in the following sentence, other than as for 'difference'.

違(ちが)うのは、　辺りに人の気配がないことくらいだ。

Answer 1

It's a way to ask questions in a polite and gentle way, traditionally you might imagine a polite lady of a certain age using this speech form.

The article https://dictionary.goo.ne.jp/jn/80375/meaning/m0u/ presents the following explanation and examples (section 2):

質問の意を表す。「お変わりありませんこと」「これでいいこと」

It feels to me that this form attenuates the question to make it sound like it is not a direct question.

Answer 2

This definition of こと corresponds to the 3rd definition under 明鏡国語辞典's entry for こと as a sentence-final particle (終助詞):

こと
〘終助〙

➌ 軽く問いかける気持ちを表す。
「お変わりありませんこと？」

And from 新明解国語辞典:

こと
(終助)
〔｢事｣に基づく〕
〔主として女性語〕

㊂ 相手に質問したり 同意を求めたり 勧誘したり することを表わす。
〔多く、上昇調のイントネーションを伴う〕

【用例】
　これでいい－
　あなたもそうお思いにならない－
　あなたも一緒にいらっしゃらない－

So it is a sentence-final particle which indicates that the speaker is asking a question. Now as for where the "gentle" part comes from, it could be a direct translation/interpretation from the 明鏡 entry, or it could be drawing from the fact that this usage of こと is generally considered to be women's language (女性語) according to some dictionaries like デジタル大辞泉 and 新明解国語辞典 which mention it in their respective entries.

To summarize, this こと (used as a sentence-final particle) is a way of asking a question, and is generally considered to be 女性語.

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The こと in the sentence you added in your edit is a nominalizing こと (e.g. the こと in 「僕は映画を観ることが好きだ」). It nominalizes 「辺りに人の気配がない」