Hi Aaqib,
GWD currently does not support fallback image.
However, you can create the same effect in GWD:
- create a YouTube component
- cover the YouTube component with the fallback image
- cover the image with a tap area component
- add event listener to the tap area to play the YouTube video on Touch / Click
- add two separate event listeners to hide the image and the tap area on YouTube component's playing event
Action => Set Styles => Choose image or tap area
Set property "display" to value "none".
Hope this helps.
Paul