Hello, it is an E61 brew group. The heating time refers to this and is approx. 5-10 minutes. However, the portafilter takes longer (approx. 15 minutes). Most people make an empty draw with the portafilter to heat it up more quickly if they want to brew an espresso more quickly. So it's true and even faster. :)
Is that enough of an answer?
Lg
Camille