>>87430974I think one major factor that is common to both examples is tinting; the character drawing is shaded like they are standing in dim lighting, but that doesn't really translate to a live2d model that needs to be 'fully illuminated' so the details pop out, and instead makes the colours and everything look flat and blend together.
(Irys herself tried to counteract this by turning the brightness on her OBS feed all the way up, which resulted in some funny interactions during collabs.)