It enables a user to submit a copy of the search result they've received from a search engine, in a manner which does not enable the user to tamper or manipulate the results received. In doing so, it enables at trustless relationship between users.
Once search results have been submitted, users visit the website to compare results between users, between queries & between search engines.
The use case builds upon the concepts of notarisation which enables the creation of signed copies of web pages, which are provably authentic & independently verifiable. Signed pages can not be modified, manipulated or tampered with by the user who created them, or any parties who received them. The signed page is authenticate in that it is represents the web page (web resource, or dom) as requested by the user, and delivered by the server.
Either through malicious intent, or technical incompetence, you can not rely on your friends to provide accurate results. Technical incompetence could include an inability to take a screenshots, taking screenshots which miss vital details, full length screenshots vs visible area of browser, screenshots which include sensitive details outside the browser window.