The following image says it all :
The images in the thumbnail are not in their perfect size. To solve this, we have to add some CSS. A css tag like following in the <head> section, after the dropzone.css will do the trick.
<style type="text/css">
.dz-image img{
width: 100%;
height: 100%;
}
</style>After adding the css tag, it wll become like following:
