  We provide a concrete criterion to determine whether or not two given
elements of PU(2,1) can be written as products of real reflections, with one
reflection in common. As an application, we show that the Picard modular groups
${\rm PU}(2,1,\mathcal{O}_d)$ with $d=1,2,3,7,11$ are generated by real
reflections up to index 1, 2, 4 or 8.
