Flickr: There is gridding on picture

Precondition:
The size of picture is more than 2200*2200 and can be shown

Reproduction Steps:
1. execute flickr.qml using qmlviewer
2. wait pictures to be downloaded
3. select any picture qualified with the precondition
4. select button [view...] to download the full size picture
5. wait the full size picture to be downloaded and shown completely

Expected Result:
Picture in full size shown is the same as the original picture

Actual Result:
There is gridding on the picture