She's not so much manic or pixie as flighty and, frankly, callous.
When a man starts warbling through Garth Brooks “Shameless,” pixie does an interpretative dance on the stage.
Noem cannot be whipped; Noem cannot vote; Noem's ambitions are as worthwhile as pixie dust in a twister.
c.1630, of obscure origin, perhaps from or relatred to Swedish dialect pyske "small fairy," but West County origin suggests ultimate source in Cornwall and thus something Celtic. Earliest references were in pixy-path "bewilderment," literally "path on which one is led astray by pixies," and pixie-led "lost."