We searched the internet for transparent pictures of empty and full jars and found what we were looking for. We finally arranged the two glasses in front of a picture of wine barrels in a wine cellar.
Credits: Adobe Stock_322110547, AdobeStock_230383727
Then we created two sections that use the variations. To create the illusion that the glass fills up as you scroll down, we selected "scroll with static background" as the transition effect.