better video image

README.md

@@ -11,7 +11,7 @@ So I wanted to publish thus people can try it and have fun with it :)
 - **Open Source** : It is completely open source and free of charge!
 - **Standards** : It works on any phone with [webgl](http://caniuse.com/#feat=webgl) and [webrtc](http://caniuse.com/#feat=stream)
 
-[![AR.js 1.0 Video](https://cloud.githubusercontent.com/assets/252962/23068128/40343608-f51a-11e6-8cb3-900e37a7f658.jpg)](https://youtu.be/0MtvjFg7tik)
+[![AR.js 1.0 Video](https://cloud.githubusercontent.com/assets/252962/23441016/ab6900ce-fe17-11e6-971b-24614fb8ac0e.png)](https://youtu.be/0MtvjFg7tik)
 
 # Try it on Mobile