Play-purty means nothing to me other than an attempt at a dialectic spelling of play-pretty. I’m sure that personally, I pronounce pretty as pritty, except on the rare occasions I want to imitate my hardbitten farmer relatives and say something is “purtier than a lil red wagon goin’ up a hill.”
Play-pretty, though sounds to me like how a villainous witch would refer to a captured hero in a fantasy movie.
“Ooh, Graymalkin, what a lovely play-pretty we’ve found. Better put it away with all the others. Cackle, cackle!”