Fergie's style, actually cool dancefloor, is using rap/hiphop elements in the lyrical structure - although she's touching just veeery slightly the artistry of traditional rappers with their pretty complex rhyme cascades.
She remembers me to the early German hiphoppers, young men (mostly non-musicians and living in ghettos as well), trying to imitate their chart idols. Well it's an optical difference between a proud black, packed with muscles and golden flamboyancy - and a shy meager caucasian, hiding under the huge hood of his fluffy grey sweater. And so is the difference in their lyrics. These German rhymes were pretty clunky, not always because it was difficult to form them correctly, but because it had a flair of coolness to make them sound harsh, and of course it was also an insurgency, disregarding established poetic tradition. Effectively a new art form emerged from these first humble efforts; still today you may stumble across such releases in the Euro area. Although that style has lost much of its piquancy down the road - not yet being really retro it may raise but a weary smile - there's enough of so-called poets who will keep it alive.