Seiso is a Japanese word that is used to describe a woman's character and
appearance.
In a general sense, it means a woman who has a humble character, a clean
appearance, uses
beautiful words, and has beautiful posture and movements.
On the other hand, in the case of neatness used in the context of Vtuver, the meaning is slightly different.
Specifically, it adds not being lewd to its original meaning.
Seiso: When a lewd topic comes up, she doesn't like it. She skillfully changes the topic to
the next one or is
embarrassed.
Not Seiso: When a lewd topic comes up, she actively uses it to
entertain and enliven the audience.
Seiso: She does not raise lewd topics. She will ignore or scold viewer comments when they are made on such topics.
Not Seiso: She may raise lewd topics to entertain viewers and herself.