What's the meaning of “but it's there”?

Question

I read in An unwanted guest by Shari Lapena the sentence below:

The younger man behind the desk does an almost imperceptible double take, but it's there.

What does it mean, but it's there.

The fuller text is here:

...he glances up when he sees her. He stops for a second, stares, and then smiles in an embarrassed way and looks away. She's used to it. She has that effect on men. As if when they see her, they can't believe their eyes for a minute. She can't help that. The younger man behind the desk does an almost imperceptible double take, but it's there. She's used to that, too...

Answer 1

I think you're right to question what it's there means in context. It means "it's present". We could easily say it's there about a look on a person's face, but with double-take, which is an action, it doesn't quite jibe.

A double-take is a delayed reaction, the act of looking away from whatever or whoever you were looking at and then immediately looking back because there was something unusual or surprising which did not register immediately.

So it would be odd to say that something which has just happened "is there".

P.S. Just guessing here, but note that the passage is being narrated in the present tense. If it had been all in the past tense, "it was there" could refer to an action like a brief, almost imperceptible double-take. It did take place. Perhaps the passage was originally in the past tense and the author flipped it to the present?

Answer 2

Although the double take was imperceptible, or hard to see/notice, it most definitely happened. That is what the author meant by saying "but it's there".