It's not a big deal, I just wondered if there was an easy fix moving forward. I would guess if you are screenshotting a pdf and saving as a jpg, the pdf might already be using a jpg in which case the jpg compression is working on what is already jpg compression. An easy fix might be to save the screenshot as a png instead of jpg, which might be good for this kind of image anyway. (Unless it's already blurry... I just saw your other reply.)
