The difference is that the headline is designed to sound mysterious. It triggers your curiosity on which the article may be about. Was it a scam? Was the dress

The difference is that the headline is designed to sound mysterious. It triggers your curiosity on which the article may be about. Was it a scam? Was the dress made out of some magic material that disappears after time? Is it even a real dress? You'll need to read the whole article to figure out what it was actually about. If the title was something like 'Investor pays 7500 for clothing image', you wouldn't have to read the article. This is known as clickbait and it is essentially 99% of marketing nowadays.