Image compression improvements would be a big help, especially if they weren't lossy recompressed if below a certain file size + resolution. Pixel art in particular gets trashed because of this. I think Old Bird Site actually had an optimization for this for a while that played nicely with pixels.
Upcoming changes to PNG image support
Historically, Twitter has supported JPEG and PNG format images. Over the years, we’ve made improvements to our image pipeline moving towards faster load times while improving quality within reasonable...
