> discard information which will contain the information with high frequency components. Now if you convert back to your regular x-y coordinates, you'll find that the resulting image looks similar to the original but has lost some of the fine details.
I would expect also the edges in the image to become more blurred, as edges correspond to high-frequency content. However, this only seems to be slightly the case in the example images.
You can see exactly that with the speaker grill and the text (This type of transformation is notoriously bad at compressing images of text, and is why you shouldn't use jpg for pictures of text)
In this context, the edges of, say, the macbook are not "high frequency" content, since they only feature one change (low to high luminosity) in a given block rather than several (high-low-high-low-high) like for the grill.
I would expect also the edges in the image to become more blurred, as edges correspond to high-frequency content. However, this only seems to be slightly the case in the example images.