At least 5, probably more, landslides have carved that valley in “recent years”. Look at the solid wall of green plants - but no trees yet! - growing up the viewer's left side. Last week's landslide/rockslide sliced all of the vegetation off down to the bare rock up high, then the “dirty grey” mass of mud and silt poured over the lower valley and filled it partially. Then the mass of more water and ice and mud carved a new groove down the right hand side of the new deposits.
Finally, the new mass of dumped rock and ice was cut down into a “new valley” of loosely pile rubble by continued water flow from above. That newest valley goes down the righthand side of the rubble.
IIRC, there was a small earthquake that dislodged some earth and rocks that then started the domino effect..........
Clearly it’s better not to live right in a mountain gorge, which describes much of Nepal and the rest of the Himalayas.
BTW, isn’t the name “Himalayas” sexist?
/rimshot