On the desktop the homepage is a Chinese handscroll (手卷): push the wheel and the scene travels sideways. On a phone that gesture makes no sense, so the same page re-reads as a hanging scroll (立軸), stacked top to bottom.
The point is that there is no second layout. One set of scenes; a media query flips the canvas from a horizontal flex row to a vertical column; and the scroll script swaps its wheel-to-horizontal logic for native vertical scrolling below 1024px. The content is written once — only the axis changes.