"Any picture on Google works." Fact: Incorrect. Random pictures can trigger trauma. Institute-approved mood pictures are vetted by psychologists for hidden triggers (e.g., a "calm" beach picture might contain a jellyfish, which terrifies a patient with a specific phobia).
: While abstract art can sometimes cause unease in patients with cognitive impairments, recognizable nature scenes universally promote a sense of safety. The Future of Visual Rehabilitation mood pictures rehabilitation institute link