I'm not familiar with this specific company but I am familiar with the pitch as there are a number of companies which provide this "service" and I've been pitched a number of times over the years.
Simply, these companies are typically looking for you to pay them for the right for you to provide Swag to Celebrities (though some companies will let you just provide the Swag).
The pitch is you "may" get some PR benefit if the Celebrity is seen wearing or using your product.
I believe in targeted PR campaign as part of our overall marketing strategy so have never participated in this kind of offer as I have never seen the value of a random program like this.
Obviously each company needs to make it's own determination whether or not this is worth the investment of product, time and money.