iphone expert

just installed a sony XAV-70bt HU. bought a iphone usb cable with the left and right audio and video out. when i play a video from the ipod side i see the video on the sony screen with the video jack plugged into aux 1 the audio does come through the usb side, but when i use an app that accesses the internet and plays video on the screen it does not come through the yellow video out of the iphone cable. Can this work is there a setting i need to change?

Thanks
jim cav