Fair Use means that the media uploaded is, basically, being used under fair use. It is most likely a screenshot from a video game, television show (like American Dad!), or a film.
Fair use is a doctrine in United States copyright law that allows limited use of copyrighted material without requiring permission from the rights holders, such as for commentary, criticism, news reporting, research, teaching or scholarship. It provides for the legal, non-licensed citation or incorporation of copyrighted material in another author's work under a four-factor balancing test.
Purpose and character
The first factor is regarding whether the use in question helps fulfill the intention of copyright law to stimulate creativity for the enrichment of the general public, or whether it aims to only "supersede the objects" of the original for reasons of personal profit. To justify the use as fair, one must demonstrate how it either advances knowledge or the progress of the arts through the addition of something new. A key consideration is the extent to which the use is interpreted as transformative, as opposed to merely derivative.
Nature of the copied work
Although the Supreme Court of the United States has ruled that the availability of copyright protection should not depend on the artistic quality or merit of a work, fair use analyses consider certain aspects of the work to be relevant, such as whether it is fictional or non-fictional.
To prevent the private ownership of work that rightfully belongs in the public domain, facts and ideas are separate from copyright—only their particular expression or fixation merits such protection. On the other hand, the social usefulness of freely available information can weigh against the appropriateness of copyright for certain fixations.
Amount and substantiality
The third factor assesses the quantity or percentage of the original copyrighted work that has been imported into the new work. In general, the less that is used in relation to the whole, e.g., a few sentences of a text for a book review, the more likely that the sample will be considered fair use.
Effect upon work's value
The fourth factor measures the effect that the allegedly infringing use has had on the copyright owner's ability to exploit his or her original work. The court not only investigates whether the defendant's specific use of the work has significantly harmed the copyright owner's market, but also whether such uses in general, if widespread, would harm the potential market of the original.