Yes, like Lily cd re mentioned, the reason that the hair is straight is because the dog was dried 100% with a high velocity dryer. For a show standard poodle this can take over an hour. For a standard in pet trim, probably about half an hour. The more often you blow dry them, the straighter the hair will remain, because it is kind of trained to be straight. My girl has never air dried and gets a bath and complete blow out every week to maintain that long straight hair. I will attach a pic I took of her a few days ago - this was right before a bath, so a week after her last blow dry. (She also had a practice spray up before this pic which I did one handed so it doesn’t look great) Her hair isn’t perfectly straight anymore but still decent.
One reason for blow drying straight is so that you can scissor the hair properly. If you try to trim curly hair you will end up with a very uneven haircut.