What is this Advertising?

We put together a brief clip of print advertisements for an array of products: body wash, toothpaste, shoes, food, even suits for men. Notice the pattern of advertisers sexually portraying women and either displaying a tiny brand/logo or none at all. In many cases, such as with the Adidas shoe and Duncan Quinn advertisements, we would have no idea what the ad was for if we weren't familiar with the brand beforehand.

Why do advertisers hide their logos? What techniques are used to attract our attention in ads like these? Is there a problem with this?