Do u want to reveal a static image OR video? The ref is for a video.
Either ways, make one animation for 1mask quad or 1video quad in one animation controller and then replicate the animation controller by copy, pasting with increment for 64 differerent boxes (images/video) and then in the scene director move the position of each animation controller as per ur requirement.
FYI its XPression and not expression :-)
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Gaurav
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