ぶりっこ / Burikko means fake cute- like a woman who wears lots of pink and acts all cutesy.
I never would have put Mayuyu in that category at all. She was very young when she first came into the spotlight, and she was very cute, nothing fake at all. And as she has matured, she has shown very interesting and unique sides of her personality. Her interest in otaku stuff, her cyborg character, plus she is very intelligent and actually seems pretty content and confident. (Burkiio types always are trying to get others to confirm how cute they are, and I do not see Mayu as doing that)
Don't know much about #1 Burikko talent- Minami Tanaka- she is a TV announcer and has been in a couple of shows. But she might be cutesy, as this is okay in the Japanese News world.
#2 Momochi from Berryz Kobo and #4 Sayumi form Morning Musume definitely have been assigned Burikko characters as part of their act, but if you see them in enough situations, it is pretty obvious that it is just an act. They are both very intelligent girls with great senses of humor.
#5 Rora (Lola) is a pretty unique character- she comes across all cutesy, but again, she is pretty comedically talented, and she is pretty fun to watch.
#6 Haruka Ayase has always struck me as more of a tomboy type, I was surprised she was on the list.
#7 Satomi Ishihara- ehhhh, maybe? but again she has always struck me as girl next door type, not over the top cutesy.