First time I've seen this. On an intercity train in Andalusia, Spain.
Doubly useful because they also serve to hold the bike in place. In France some trains have (lockless) racks with bungees which you pull over the bike.
Both ideas seem to be experimental replacements for the more common hanger racks (where you hang the bike by the wheel). Those were never great for tourists with paniers and they're becoming untenable in the era of weird-geometry bikes and, um, fat lazy electric ones like the one you see there.
