Metadata is all about being descriptive.

Titles should be the main focus of an item. In terms of images and GIF files, the title is the main identity aside from its appearance. It needs to be short to give users the main intent or message the image wants to express. It can be the name of a character or the caption below the image if available. In giving more explanation and background, the description needs to be a little longer, and it speaks more information regarding the image, typically about its background and what is the action or movement of the image. It describes what is supposed to be happening in an image to prevent misinterpretation. In the context of websites, when the image itself is corrupted or the connection is not that strong enough, the description is shown as the alt text. For the subject, relevant terms are needed to be shown to be categorized and tagged with other images with the same term. The terms can be a notable character or person in the image, the reaction it is expressing, or the show, video, country, etc.