Many old links have expired (eg. TinyURL and puush ones), so I'll be updating this thread with the missing shinys.
Below is a list of the links that are broken and whose screenshots are needed.
If you would like a chance for your shiny to be featured, kindly upload a screenshot of the shiny's Summary Page on https://imgur.com/upload and DM me the link.
Gen 1
Seel - Omanyte - Omastar
Gen 2
Cleffa - Unown (C, D, J, K, L) - Blissey
Gen 3
Combusken