This image is copyrighted to Blizzard Entertainment Inc.
However:
Blizzard Entertainment Inc. grants "a personal, non-exclusive, non-transferable and non- assignable license to use and display, for home, noncommercial and personal use only, one copy of any material and/or software that you may download from [their] site, including, but not limited to, any files, codes, audio or images incorporated in or generated by the software (collectively the "Downloaded Content") provided, however, that you must include or maintain all copyright and other notices contained or associated with such Downloaded Content."
Furthermore, we believe this falls under American fair use law because: It does not limit the ability of the owner to profit from the image in any way; It is used solely for the purpose of providing illustration and a guide to Blizzard Entertainment's products.

Wikia

Media in category "Companion screenshots"