My how she's changed. When Hot Press first encountered St Vincent's Annie Clark in 2007, the singer was an archetypal indie-pop ingenue. With her charity shop beret and sweet, unassuming manner, the pale Texan came across as likeable but somewhat lost and vulnerable. She looked in need of a hug and a square meal.

Eight years on, she is a wildly different proposition. By dint of her public friendship with super-model Cara Delevingne, Clark is now properly famous (google her and the first 10 entries are from the Daily Mail). But celebrity has come at the right time for the 32-year-old who, with 2014's St Vincent album, reinvented herself as otherworldly rock maven – a sci-fi figure with Edward Scissorhands hair and a line in stomping outsider pop. A glorious whiff of contrivance attended her makeover: here, at last, was a contemporary songwriter who understood that pop functions best as a playground for the imagination – that dressing up and presenting an exaggerated vision of yourself is part of the fun.

At the start of a brief Irish tour, she doubled down on the high-concept eccentricities. As night stole over the Iveagh Gardens, Clark stood atop a raised plinth, surveying the venue with studied imperiousness. She plunged into a bucking guitar solo on 'Cheerleader', a rumination on gender fluidity with elements of John Hughes teen-melodrama and, on 'Rattlesnake', jerked and piouretted across the stage, like a edgy, damaged Beyonce.

Throughout, her shredding was a thing to behold, confirming Clark as among the most exciting guitarists in contemporary rock, capable of blitzkrieg riffs without ever descending into dreary showboating. This is how it's done, boys.

Along with the archness and the studied hauteur, Clark is a smart writer with intelligent observations about life in the social media age. Most pointed of all is Digital Witness, a skewering of the modern tendency to document life via Twitter and Facebook rather than experience it in the moment. As she reached for the chorus all around me smartphones were raised in a gesture of unthinking supplication – thus making Clark's point for her.

Did something like a smile play across her face ? It seemed possible: behind the robo-queen persona, glimpses of twinkling wit were ever-present– a wryness that let you know that, ultimately, this was all just a delicious piece of theatre.