James, yup - Speedlights. Up to four of them, depending - most show three - one as key in a small softbox, one as fill in an umbrella, and one, the backlight, on a small tripod on the ground behind the dog to the left, angled to spray light across the backdrop with the wide-angle diffuser down. If I face the little IR sensor on the Speedlight towards the camera position, even in broad daylight, such as this (I'm under a pavillion), they fire fine.

Sometimes, I'll have a fourth as a rim light (need to use a gobo (bo-between) to keep flare from occuring in the lens, and sometimes I'll put one in a small softbox directly over the subject as well.