From Meta, a Wikimedia project coordination wiki
You should read firstly Oversight!
It is not possible to oversight an image by using oversight interface! But, we may try to imitate it.
- Note for stewards: You have to be admin on the particular wiki, being an oversight is not enough.
- Delete the image. (If image is sensitive, like uncovering someone's identity, it is better to delete the image ASAP because it may be cached on proxies.)
- Go to deletion log.
- Find the link to the image (not the link to the text of the image). Click there and find the file name. It will be at the end of the link and name will be some not-so-human-readable hash; something like: rueqwiop5412rfjalre1321.jpg.
- Tell to administrators of Wikimedia servers (usually, by going to #wikimedia-tech channel) the name of the deleted image.
- If you are an oversight or steward, consider that we should organize our work in such manner which wouldn't overflow administrators of Wikimedia servers.
- If something is really urgent (like uncovering someone's identity on projects with 100+ admins), ask administrators immediately.
- If it is not so urgent (not a lot of admins on the project), we should make some queue for deletion which should be executed, let's say, once per month.