David,
With query wrangler create a new query of the “widget” type.
Change the Row Style to ‘Fields’
Under Fields click add fields and add Image Attachment. Once it’s added click on the Image Attachment link & configure what size you want image to display & whether or not it should link to the post.
Aside from customizing the number of posts under posts per page & maybe limiting the type of posts via Filter you are done.
Hope this is helpful.