Shrine for the wish-granting child-spirits mrieng kongveal, “children lords-fields). The little red objects are clothes – these spirits are naked except for a red and black chequered scarf (the traditional Khmer krama), and should be given a suit of red clothes when they join the household.
Aside: the colour red is closely associated with spirits and magic, just as yellow is associated with the Buddha and the monkhood. Just why this is so I have no idea. I’ve been told by Cambodians that it comes from Chinese influence, but I doubt it – this holds true across the Buddhist part of Southeast Asia.