Almost all of the images I have been replacing are done so by one or more of the following criteria:
1. The image is of equipment that is out of date, missing jobs from the Seekers of Adoulin expansion.
2. The image is not uniformly cropped, clipping the outer boundary of the game's infobox or containing visible background imagery from the screenshot.
3. The image does not use an opaque window background.
4. The image is watermarked or otherwise clearly originated from a 3rd party site without attribution.
I have not explicitly been targeting your contributions. If there was a change you feel was done in error let me know and I can revert it.
The jpg-pictures i made were cut by paint after i switched to a non-transperant background ingame and screenshotting it myself with hardcopy. I tried to make it as legal as possible by adding the data-info. All of them were taken, while i did the quests at the time of the upload. I choosed jpg cause it took less bites. It made sense to change the name of the trial as picture-name into the itemname with it's current level on the picture. But to me it looked like exactly the same picture got placed, just with another namecode in the editpage and png instead of jpg. Made me ask myself why i did the work. That's all. When it tried to use the "[[..."-command to add the item name with the wiki-automatism like Gungnir (80) what actually works, I thought to have to make my own pics. Because i didn't find a data. And i tried the png-ending also. FFXIclopedia should show more already exiting pages, when you use this.
As far as Gungnir (80) goes, the picture that was originally there was named File:Gun4.jpg, created almost nine years ago. Convention asks that images be named after the item they describe without abbreviation and 'Gun4.jpg' was deemed too ambiguous. I capped the replacement myself and saved it as , PNG as I find that format easier to work with, and replaced all instances of File:Gun4.jpg with the new image, then removed Gun4.jpg once it was no longer used on any pages. Unfortunately wiki does not make it possible to preserve the file history of a .jpeg replaced by a .png as there is no way to modify the reported MIME type of an uploaded image page. The only replacement strategy that works is what I have just described.
I apologize if this makes your efforts feel futile. Understand that my goals here are to update as many item pages as possible so that they can be reliably included in modern templates being developed that make the site more mobile-friendly as well as use modern features on the desktop browser version of the site. This often includes replacing images to meet this wiki's media naming and image policies, both decisions intended to make it easier for active wiki editors to make more changes down the road.