The columns and supporting posts have different jobs, so for design, cost and aesthetic reasons it often makes sense to place them separately.
You may want the columns to be placed in a way that visually aligns with the first or second floor or with the stairs, but the posts to be placed in a way that is more coupled to the framing or footing layout, neither of which have to visually make sense.
You may want the columns to be ornate, like yours. It's harder if not impossible to find ones like that that also extend an extra several feet towards the ground. You would also need to buy columns capable of supporting the deck and whatever is above, rather than just the latter, which would be a lot more expensive if they were also ornate.
In your case it looks like there is one column, it's in the corner, there is a post in the corner, and if you are happy with the appearance of a 6x6 square column, most of those considerations don't apply.
But even then: Look at the "example" you posted. The beam, along the front, has to sit on top of the posts and you can see how it's notched into the posts in order to achieve that. If you extend those posts all the way to the ceiling, as they did, it means they have to be all that much bigger. That's more expensive, and also visually much heavier. Whether or not that matters is up to you.