This is how Ms. Netrebko, 47, has become the most captivating opera singer of our time: She defines “extra.” She pushes herself to her limits, and then goes a step further, usually in purple mink. She embodies an excess that lies at the molten core of opera, and which spills into the images she unloads online.

Not only does the garnet glint of her voice make you want to gussy up for the opera, but it also makes you want to gussy up for life, to race out onto your snow-covered high-rise balcony in your bathing suit, just like she does.

How many of us have longed to don a poncho and hot pants for an excursion to Denny’s? Or known deep in our hearts that the only acceptable fabric for a sweatshirt is lamé? Ms. Netrebko brings the thrill of possibility to all these reveries, which for her seem like not at all an act; she manages to make being over-the-top a vehicle for authenticity.