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The last two on page 7 is Skyler scenes, so re-play the date with her to un-lock them. I have not figured out to un-lock the last two scenes on page 6, which I guess are Jessica scenes.
To unlock the hidden renders, you have to find the exact right moment in the scene where the extra feature appears to unlock the render, which requires a good deal of attention. The hints only help you of where you need to pay extra attention, not the exact moment.

You click on the skill you want to upgrade for about two seconds, keeping the mouse button down the whole time.