The smiling picture focuses on features ('remote logginf for IOS apps), where the normal page focuses on benefits ('Start Building Better iOS Apps Today'). Also

The smiling picture focuses on features ('remote logginf for IOS apps), where the normal page focuses on benefits ('Start Building Better iOS Apps Today'). Also, the layout/contrast is different. To get meaningful results out of your A/B testing the number of variables should be as little as possible. So if your premises is 'smiling people convert better than a picture of an iPhone' you should keep every other detail the same.