Serious journalists don't usually engage in this empty ritual. They need to spend extended time with the subject, like a fly on the wall, seeing what the big name actually does, in contrast to what he says he does.
ここに出てくる "a fly on the wall" は慣用句のテキストで覚えた単語ですが、実際の文章で見るのは初めてなので取り上げました。 壁に停まってじっとしている蝿は何をしているのでしょうか?
・Collins English Dictionary: a person who watches others, while not being noticed himself or herself: The fly on the wall could soon be listening in - with scientists developing insect-inspired surveillance robots.
・Wiktionary: A quiet, non-participating, or unseen observer; an eavesdropper or witness.
・Cambridge Dictionaries Online: If you say that you would like to be a fly on the wall on an occasion, you mean that you would like to hear what will be said or see what will happen while not being noticed: I'd love to be a fly on the wall when those two get home!
"fly-on-the-wall" となると形容詞になり、次ぎの様な意味でも使われるとCambridge Dictionariesに書かれています。
describes a television programme in which the people involved behave normally, as if they are not being filmed: a fly-on-the-wall documentary