I know who she is, it's my first time uploading an image using this website and I don't know how to set the tags.
On the upload screen, you type the tags in the big text box under the rating selection. If you're uploading from your computer instead of a URL, you'll also need to change the source to the URL you got it from. If you extracted this from the game assets, then you can put a note indicating this instead of a URL. There's also a tab above the rating selection that will show the source field when clicked.
For file that are already uploaded, click Edit under Options on the left side of the screen or type e on your keyboard to bring up the edit page, where you can change tags, ratings, the source, and more.