Mega compression artifacts on the Amazon Cloud Drive

Opinion: After Amazon had now unlocked the cloud for photos with unlimited storage, I tried my luck and invited 2 JPGs high (each with high resolution with ca 5100x3400px resolution, many homogeneous surfaces, so only good 6.5MB file size). (!) The same files I have on the Amazon Cloud Drive viewer and each with the original file in the comparison (a) on the Fire TV (with connected Philips Cinema 21: 9 TV with DLNA vs. Amazon Fire TV), (b) on the laptop (wide color gamut, color calibrated, FastStone vs the Amazon Browser Viewer in Firefox) and (c) on the tablet (Galaxy NotePro, QuickPic vs. Amazon Cloud Drive Viewer) considered and compared.

Result:
(A) On the Fire TV there was MEGA excessive artifacts. Apparently Amazon compressed files mercilessly down for viewing
(B) On the PC browser, it was slightly better than on the Fire TV, but still with extreme compression artifacts
(C) On the Tablet saw it still 'somewhat useful' - but even there, there were significant JPG artifacts.

Conclusion: Amazon Cloud Drive Viewer - nice for undemanding photo users who 'sometimes just a snapshot' want to watch; unusable (at least in the current version on Nov 2014) for users with high demands on image quality during playback.

PS: If you can not do anything more with the term artifact - on Wikipedia, there are in "Artifact (Computer Graphics)" a viable definition.