  We give a description of Nurowski's conformal structure for some examples of
bracket-generating rank 2 distributions in dimension 5, aka
$(2,3,5)$-distributions, namely the An-Nurowski circle twistor distribution for
pairs of surfaces of constant Gauss curvature rolling without slipping or
twisting over each other. In the case of hyperboloid surfaces whose curvature
ratios give maximally symmetric $(2,3,5)$-distributions, we find the change of
coordinates that map the conformal structure to the flat metric of Engel. We
also consider a rank $3$ Pfaffian system in dimension 5 with $SU(2)$ symmetry
obtained by rotating two of the 1-forms in the Pfaffian system of the spheres
rolling distribution, and discuss complexifications of such distributions.
