How can i pin the mockup on the rectangle that unblurs it?

In below picture, I want to make " Unblurring Glass Effect" with frame but i can’t pin mockup to left rectangle.

I want to see this : When i move the mockup, image in the mockup will be unblurring.

Hello guys. I’m interested in UI design like 7 months. I try to make different designs by myself.

In below picture, I want to make " Unblurring Glass Effect " with frame but i can’t pin frame to left rectangle. I want to see this : When i move the frame, image in the frame will be unblurring.

Any ideas about it ? Thx.