Forgot we are getting screenshots as JPG.

lib/roles/device/plugins/screenshot.js

@@ -32,8 +32,8 @@ module.exports = syrup.serial()
           }
           else {
             resolve(storage.store('image', res, {
-              filename: util.format('%s.png', options.serial)
-            , contentType: 'image/png'
+              filename: util.format('%s.jpg', options.serial)
+            , contentType: 'image/jpeg'
             , knownLength: +res.headers['content-length']
             }))
           }