Licensing

This is a copyrighted file, and its copyright is most likely owned by either the publisher or author of the work. It is believed that its use here constitutes "Fair Use" given that...
...it is used in a non-commercial setting, and therefore is not being used to generate profit in this context.
...its use here does not significantly impede the right of the copyright holder to sell the copyrighted material.
...it is used in a largely unaltered state, where any editing has been done purely for cosmetic/display purposes.
...it has no free alternative that could illustrate the same meaning.