I wouldn’t say it’s blurry when viewing it in in full resolution, but it’s hard to tell since I didn’t see the original picture.
The problem could be caused by the browser, which is resizing the picture automatically depending on the device resolution.
Pictures are resized to fit in 540×1000px and saved. then they are resized by your browser depending on the device resolution.
-- Michal, http://cakesdecor.com | My Facebook: http://www.facebook.com/michal.bulla