at the top / in the top

Question

Here are two examples from a computer book that are used right on the same page (to be more specific, the examples come from this book: Access 2013: The Missing Manual by Matthew MacDonald):

The logo is a tiny picture that usually sits in the top-left corner of a report, next to the title.

A little later on that page it says:

The logo and title typically sit at the top of your report.

I was taught that you should always say at the top-left corner of something, but in the first of the two examples the author, as you can see, says in the top-left corner of. Do you think his English there is totally fine? Maybe, his choice of words has something to do with the fact that there is some sort of spatial implication that the thing he's talking about is contained within boundaries rather than at a certain point as is the case with the at version (the corner of something can be thought of as a point and for points we usually use at)?

Answer 1

Short answer: The word "in" is idiomatic with corner, so I see nothing wrong with the author's wording.

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Longer answer:

I was taught that you should say at the top-right corner of something

I don't know where you learned that, but always be skeptical of a simple rule that always tells you which preposition is right – particularly if you think any other preposition would be wrong. These little words are more flexible than a gymnast!

Even without the word corner, I think I prefer in over at or to, although none of these seem "incorrect":

The logo is a tiny picture that sits in the top left.
The logo is a tiny picture that sits at the top left.
The logo is a tiny picture that sits to the top left.

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The only 100% accurate, hard-and-fast rule is that there is no 100% accurate, hard-and-fast rule. I can use several prepositions to accurately describe the locations in this picture:

1. The logo goes at the top left
2. The site name goes at the top beneath the logo
3. The site branding goes in the center at the top
4. The site utilities go in the top-right corner
5. The navigation bar goes below the header and above the body
6. The section navigation goes in the body to the left

However, these are okay, too:

1. The logo goes on top and to the left
2. The site name goes in the header below the logo
3. The site branding goes in the middle above the navigation bar
4. The site utilities go at the top and to the right
5. The navigation bar goes between the header and the body
6. The section navigation goes at the left of the body

Answer 2

Both are in practice. Logo 'in' and 'at'.

Here, 'at' typically talks about the point. However, in is a bit broader. I work closely with web designers and use it that way quite often.

For instance, "put the sub-menu in the left side of the page". I'm talking about the place in a broader sense. But then if I say, "put the submit button at a left right bottom" I am specific about the place because 'at' will point out the place.

But, don't get driven by the nuance of 'at' and 'in'. In fact, I'd prefer the third option 'on' over 'in'!