GWT seems to be currently unable to download any images. The tasker goes wild, see the logs with thousands of identical entries:
https://commons.wikimedia.org/w/index.php?title=Special:Log&offset=&limit=5000&type=gwtoolset&user=
(...)
18:38, 16 January 2015 Swiss National Library (talk | contribs) metadata job created. <h2>Step 4: Batch upload</h2>Metadata batch job created. Your metadata file will be analyzed shortly and each item will be uploaded to the wiki in a background process. You can check the page "<a href="/wiki/Special:NewFiles" title="Special:NewFiles" target="_blank">Special:NewFiles</a>" to see when they have been uploaded. Started with metadata record 1.
18:38, 16 January 2015 Swiss National Library (talk | contribs) metadata job created. <h2>Step 4: Batch upload</h2>Metadata batch job created. Your metadata file will be analyzed shortly and each item will be uploaded to the wiki in a background process. You can check the page "<a href="/wiki/Special:NewFiles" title="Special:NewFiles" target="_blank">Special:NewFiles</a>" to see when they have been uploaded. Started with metadata record 1.
18:38, 16 January 2015 Swiss National Library (talk | contribs) metadata job created. <h2>Step 4: Batch upload</h2>Metadata batch job created. Your metadata file will be analyzed shortly and each item will be uploaded to the wiki in a background process. You can check the page "<a href="/wiki/Special:NewFiles" title="Special:NewFiles" target="_blank">Special:NewFiles</a>" to see when they have been uploaded. Started with metadata record 1.
18:38, 16 January 2015 Swiss National Library (talk | contribs) metadata job created. <h2>Step 4: Batch upload</h2>Metadata batch job created. Your metadata file will be analyzed shortly and each item will be uploaded to the wiki in a background process. You can check the page "<a href="/wiki/Special:NewFiles" title="Special:NewFiles" target="_blank">Special:NewFiles</a>" to see when they have been uploaded. Started with metadata record 1.
18:38, 16 January 2015 Swiss National Library (talk | contribs) metadata job created. <h2>Step 4: Batch upload</h2>Metadata batch job created. Your metadata file will be analyzed shortly and each item will be uploaded to the wiki in a background process. You can check the page "<a href="/wiki/Special:NewFiles" title="Special:NewFiles" target="_blank">Special:NewFiles</a>" to see when they have been uploaded. Started with metadata record 1.
(...)