Lower QR thumbnails resize threshold. Background images are not applied under the borders, so it is now adjusted.

css/style.css

@@ -577,8 +577,8 @@ a[href="javascript:;"] {
   box-sizing: border-box;
   cursor: move;
   display: inline-block;
-  height: 90px; width: 90px;
-  margin: 5px; padding: 2px;
+  height: 92px; width: 92px;
+  margin: 4px; padding: 2px;
   opacity: .6;
   outline: none;
   overflow: hidden;

src/qr.coffee

@@ -474,6 +474,7 @@ QR =
           reader.onload = (e) =>
             @setThumbnail e.target.result
           reader.readAsDataURL @file
+          return
       else
         fileURL = URL.createObjectURL @file
 
@@ -484,10 +485,10 @@ QR =
         # Resized pictures through canvases look like ass,
         # so we generate thumbnails `s` times bigger then expected
         # to avoid crappy resized quality.
-        s = 90*3
+        s = 90*2
         {height, width} = img
         if height < s or width < s
-          @URL = fileURL
+          @URL = fileURL if window.URL
           @nodes.el.style.backgroundImage = "url(#{@URL})"
           return
         if height <= width