In the realm of optoelectronics and nanophotonics, controlling excitonic emission in van der Waals (vdW) layered heterostructures holds significant promise. In this study, we explore mixed-dimensional heterostructures comprising lead iodide (PbI₂) nanowires and tin sulfide (SnS) flakes. Our findings indicate that the exciton energy transfer at the heterointerface is distinctly influenced by contact geometry. Employing vapor-liquid-solid (VLS) growth with lead catalysts, we synthesized two types of PbI₂ nanowires oriented along [001] and [010] directions. These nanowires, with their sidewall facets, namely (100) and (001) planes, establish unique contact interfaces with the (001) plane of SnS flakes during the dry transfer process. Structural characterizations paired with optical techniques like photoluminescence (PL) and cathodoluminescence (CL) show that excitonic excitations in PbI₂ nanowires can transfer to SnS via their sidewall edges, thereby inducing luminescence in the SnS. Notably, the vdW contact geometry significantly enhances the excitonic emission from SnS domains at the PbI₂(100)/SnS(001) heterointerface in comparison to the PbI₂ (001)/SnS(001) contact. This transferred energy effectively propagates along the SnS domain edges, following a guided mode. Our research offers a novel strategy for tailoring excitonic emissions in vdW heterostructures, paving the way for advanced applications in the field.