Morrison's conjecture on geometric transitions and mirror symmetry

Let $\widehat{X}$ and $\widetilde{X}$ be Calabi--Yau manifolds, and suppose they are related by a geometric transition

$$\widehat{X} \dashrightarrow X \rightsquigarrow \widetilde{X},$$

where $\widehat{X} \dashrightarrow X$ is a birational contraction and $X \rightsquigarrow \widetilde{X}$ is a smoothing. Suppose $Y_1$ and $Y_2$ are the mirrors of $\widehat{X}$ and $\widetilde{X}$ respectively. Morrison's conjecture. There exists a geometric transition

$$Y_2 \rightsquigarrow Y \dashrightarrow Y_1$$

relating $Y_1$ and $Y_2$. The conjecture predicts that geometric transitions are reversed under mirror symmetry; the paper provides supportive evidence through SYZ mirror symmetry for punctured generalized and orbifolded conifolds.