Wix has released a great new tool (to beta only) called the Hoverbox, which is essentially a super customizable rollover button. Here I show you how to add a Hoverbox, and how to add elements/animation/video to the regular or hover’ed instance. Learn more in my Wix Designer blog:
https://www.picklewix.com/single-post/2017/01/04/Wix-Rollover-Buttons-Hoverbox

Note: the Wix Hoverbox is still in Beta mode, so it is not yet available to all Wix editors, but Wix hopes to release it soon! (Maybe in July 2017?)

Also, in the meantime until the Hoverbox is released to the public, and you just want to add a simple “hover” color effect to any image, here is my post on how to do it:
https://www.picklewix.com/single-post/image-Rollover-Effect-in-Wix