one viral AI avatar or “Barbie Box” image can consume enough energy to fully charge an electric car several times.

A Model 3 battery is ~200,000 kiloJoules.

Absolute worst case for an image, even taking extreme estimates and amortizing out all the training, is like 20kJ. Maybe 60kJ for a slop video that takes under a minute to render, which is on the order of browsing Lemmy on a laptop for a bit.