This Scrippy opens the blinds from the center in opposite directions.   To create this, I inserted a positioned container, and then inside that container I inserted the butterfly image and another positioned container to hold the two blind scrolls. 

The first scroll is set to scroll up and the starting position is set at a minus 146.  This is half the width of the butterfly graphic and a minus sign is used to move the image up from center. 

The second scroll is set to scroll down and the starting position is set at a plus 146.  This moves the graphic down from the center.

Since I only want it to open once, I entered a large number in the space between setting for both scrolls.  Make sure that you use the same scroll speed for both scrolls.