Search results WebPart in SharePoint 2013 publishing site

I added Search results WebPart in SharePoint 2013 publishing site. I edited the webpart Changed the query:

Select query to Picture(System)
Restrict by app : specify a URL and pasted my picture library url.

added the webpart published the page. went to the page where i added the webpart i can see the links and images on right saying i have 7 results.

but when i sign off the user by puting publishing site to anonymous user. 

i see Nothing here matches your search 

why it is not showing the same results for anonymous user ??

Thanks,
M.M