Valentine book (pt. 5): flipping tab

Need: I have two similar but opposite photos that I want to flip back and forth at the pull of a tab. 
Mechanism used: pull-strip with flap that lifts up in opposite direction of the pull.
Why it works: the slot in the page acts as a fulcrum for the two little tabs to move behind the page. 

That's all for my Valentine's Day book! I'm stoked for how it's turning out so far but also equally as stoked that I'm getting better with time management to fully finish my personal projects.