What does “to look by” mean?

According to an article I read, the following sentences are roughly synonymous:

1. He looked by the building.
2. He looked past the building.

I don't know what look by and look past mean. I found a dictionary says that to look past means to “look at the (back)side of something”. Is that dictionary right?

Anyway, I would please like to know what look by and look past mean.

Solution 1:

Look past means look at a point beyond. You might

Look past the building at the shop down the street or, figuratively,
Look past his opinions to his actions.

I don't know on what authority your article suggests that look by is a synonymous with look past. I have never encountered that idiom. The only sense I can immediately make of look by is look at a point next to:

Look by the building for an alley running north.
*Look by the computer and you'll find a notebook.

By here is simply a preposition, heading a prepositional phrase of direction. Look past is probably to be parsed similarly, but it "feels" a bit more like a phrasal verb, perhaps because it is used figuratively as well as literally.

Solution 2:

• to look by something = to look near something
• to look past something = to look beyond something
• to look around something = (usually) to look within something; (rarely) to look beyond something

If you need to find something and are told to look by the house, you should look for your missing object in the house’s close proximity — that is, to search for it near the house.

But if you are told to look past the house for it, you have to keep going beyond the house to something beyond it before you can look.

Interestingly, to look around is also open to multiple readings, although by far the most common sense is more like look by than look past. You look around your house for something, or you look around the back fence. (If someone is just looking around, though, they are casting their gaze in many directions.) Only rarely does one look around an obstacle blocking one’s view. Normally one just looks around a house or a garden or a backyard, where it means within.

Also, to look around for something is different again.