  Brane brick models are Type IIA brane configurations that encode the $2d$
$\mathcal{N}=(0,2)$ gauge theories on the worldvolume of D1-branes probing
toric Calabi-Yau 4-folds. We use mirror symmetry to improve our understanding
of this correspondence and to provide a systematic approach for constructing
brane brick models starting from geometry. The mirror configuration consists of
D5-branes wrapping 4-spheres and the gauge theory is determined by how they
intersect. We also explain how $2d$ $(0,2)$ triality is realized in terms of
geometric transitions in the mirror geometry. Mirror symmetry leads to a
geometric unification of dualities in different dimensions, where the order of
duality is $n-1$ for a Calabi-Yau $n$-fold. This makes us conjecture the
existence of a quadrality symmetry in $0d$. Finally, we comment on how the
M-theory lift of brane brick models connects to the classification of $2d$
$(0,2)$ theories in terms of 4-manifolds.
