Flickr offers three different content type categories. Putting your content into the correct category is important as it ensures members view the type of content that they want to view.
They content type categories are as follows:
- Photos / Videos
- Illustration/Art / Animation/CGI or other non-photographic images, or
- Screencasts / Screenshots - what's a screenshot
When you upload content to Flickr, you need to choose where it "fits" in these categories. For example, if you want to upload a screenshot of an online game (e.g. Second Life), you can, but you need to flag it as a screenshot.
Also, remember that it is against Flickr guidelines to upload content that you do not own the copyright to. For more information on copyright guidelines see this article.