e621:image_quality

howto:sites_and_sources#twitter

Here's pretty much whole answer.

TheOmegaAlpha said:
I don't think a larger image is higher quality, the full size is definitely more pixelated. Is it wrong to post a smaller, clearer image? I don't want to have them deleted in the future.

What you are getting is supersampling effect. You are constraining high amount of detail in small area, meaning that all the smaller mistakes get smoothed out and with twitter applying high amount of JPG compression, lower resolution also has smaller areas of single color which makes compression artifacting less noticeable, even though it's identical.

So there are reasons why smaller version might initially look better for you, but it's definitely not. Especially when you start to look up finer details on the image, it gets clear that lower resolution kinda mushes them together.

Here's comparison of your upload on left, new upload on right, something like eyelashes you can't even see if they exsist on your upload:
https://puu.sh/D022N/456860765b.png

As others have been discussing above, neither versions are ideal as both are compressed to shit, so most ideal situation would be to get copy from artist directly or from website that does not fuck the files to this degree, thus far only twitter and furaffinity are found and both destroy artwork.

TheOmegaAlpha said:
I'm sorry, I don't think that answers my question.

TheOmegaAlpha said:
Thank you all for the repetitive information, I'm sure I'll get it in a few more times.

What kind of answer are you then wanting? Because you asked question and it was answered, but you are refusing the answer because you didn't like it.

The higher resolution image in this case is also higher quality and we try archive highest quality variations. To avoid further deletions like this in future ensure you are getting highest quality version from the website you are getting the artwork from.

Also it's technical limitation of the website, generally one post can only have one file attached to it, so to replace the file, new post has to be made and old deleted.