Wow!
So I thought.... hmmm how am I going to pick out what to animate etc... so thought I'd just paste in what I wanted to do... like this...
TweenMax.to('#image1' ,2 , {'-webkit-mask-image': '-webkit-linear-gradient(left, rgba(0,0,0,0) 0%, rgba(0,0,0,0) 100%, rgba(0,0,0,1) 105%, rgba(0,0,0,1) 100%)'});
...and it worked! I can knock off early now (I wish)
James