Two dots, a small mouth, and a rounded silhouette do more work than a crowded character sheet. Rilakkuma's face looks almost underdesigned. That restraint is the point: visual-perception research suggests that low-detail, predictable cues can reduce processing load, leaving the brain with fewer signals to sort and fewer surprises to defend against.
Cute is not the whole explanation. Perceptual fluency rises when a viewer can identify a form without repeatedly testing its meaning, and rounded contours tend to read as nonthreatening rather than sharp or unstable. The system relaxes. Before conscious judgment takes over. In predictive coding terms, the face supplies a small set of expected signals; low prediction error means less need for corrective attention. That does not make a cartoon therapeutic, but it can make looking feel less effortful.
This is design's quiet hack. Predictive coding can resemble a background process: a stable face keeps checking demands low, while autonomic regulation may respond to fewer cues associated with alarm. The analogy is not literal. Still, the commercial lesson reaches beyond toys. Products that use legible shapes, restrained signals, and repeatable visual grammar may earn attention without exhausting it. That matters to users. In a screen culture built to provoke scanning, systems that minimize visual uncertainty could reduce friction for many viewers before any instruction is read. The bolder prospect is humane interface design that treats calm not as decoration, but as a measurable operating condition.