Not always infinite. If you set it to be the top posts for the last 12 hours for example, it isn’t that hard to get to the end, not like automatically chosen posts follow on or are inserted into that feed.

That’s not the cup, as it says on it the brand is Yeti. I have one, it is larger than average but not anything like 1.5L.
Here it is:
https://au.yeti.com/products/rambler-14-oz-2-0-414-ml-mug?variant=41262301053062

14oz / 414ml