Snap2Review: Vision-Grounded Retrieval and Pairwise Preference Alignment for Personalized Reviews Generation

摘要

Personalized review generation is vital for e-commerce engagement, yet integrating user-provided images while maintaining distinct user personas remains a critical challenge. Existing methods often struggle to bridge the semantic gap between objective visual signals and subjective linguistic patterns, frequently resulting in hallucinations or homogenized, impersonal content. To address these limitations, we propose Snap2Review, a novel framework that harmonizes cross-modal retrieval with fine-grained preference learning. First, we optimize a cross-modal retriever that maps visual features directly to semantically related historical reviews, using these interactions as precise anchors to strictly ground the generation. Second, we introduce Tri-DPO, which employs a stratified negative sampling strategy with varying difficulty levels, ranging from obvious errors to subtle stylistic mismatches, to force the model to discern fine-grained user preferences. By distinguishing these fine-grained nuances, our model moves beyond generic praise to accurately mimic the user's authentic writing style. Extensive experiments on real-world datasets demonstrate that Snap2Review significantly outperforms strong baselines in both relevance and personalization metrics.