Structure of lead(II,IV) oxide
What you call a molecular structure is in reality an asymmetric unit. These two terms are not related, and in general are not interchangeable. The same way $\ce{Pb3O4}$ is not a molecular formula, but a formula unit. 

All pictures you presented are correct in terms that they do represent an asymmetric unit, but actually an IUCr-recommended asymmetric unit (can be generated with Olex2's command standardise) looks like this:

$\color{#FF0D0D}{\Large\bullet}~\ce{O}$;
$\color{#575961}{\Large\bullet}~\ce{Pb}$.



... and with $Z = 4$ these are packed in a unit cell with $Pbam$ space group accordingly:




The crystal structure itself can be represented as infinite layers of cross-linked chains made of $\ce{[PbO6]}$ octahedra, which are stacked via $\ce{- O-Pb-O -}$ bridges:



Crystallographic data is taken from ICSD #9753 [1].


Gavarri, J. R.; Weigel, D.; Hewat, A. W. Journal of Solid State Chemistry 1978, 23 (3), 327–339. DOI 10.1016/0022-4596(78)90081-6.