On instagram in google chrome or chromium engine browser right click the image on the bottom click developer / Inspect element on the right in the tab elements you will see direct link to the picture in various resolutions - 1080w is the highest version (when not logged in) - even higher resolution with tools
there are different versions of the pic served to clients based on resolution of device / window
bonus some original boob photos
I'm not good a photoshop, but I thought I saw a little outline so I figured I'd mess with it a bit and there was a little something
maybe someone who is better with photoshop can improve on this,