It's crazy how complicated design is since there are so many form factors to get right. Miss one, and you lose part of your audience.
I have so much respect for front end engineers and designers, because this stuff is not easy.
Commenting on the design, as a slow reader and non-native English speaker I felt annoyed at having to read against the clock ticking away for each slide (or alternatively, having to click 'pause' again for each slide individually). I hope whatever package this page is based on changes their default settings in future releases.