The first photo was posted by Robin Williams on his birthday (20 days before he died). In the second photo, he is congratulating his daughter on her birthday (2 weeks before he died).

Robin Williams suffered from dementia with Lewy bodies. When a person has this type of dementia, they can’t lead a normal life: they can’t think, sleep, or believe what they see, and they can’t be happy. The actor couldn’t handle it and committed suicide.