A mirror benchmark for vision-language models found that giving them depth data actively hurt their reasoning
AspireAI community · arXiv
Vision-language models are assumed to benefit from depth data, but mirrors break that assumption: they distort depth readings while reproducing object appearances, so a reflection looks like a real object. MIRA-Bench was built from a mirror-centric RGB-D dataset of 1,011 images collected across 525 real-world scenes, six reflective surface types, and daytime and nighttime conditions, with masks for reflective regions and for directly observed versus mirror-reflected objects. The benchmark holds 14,140 QA pairs across eight sub-tasks in three cognitive levels - reflection-aware perception, spatial reasoning and scene-level decision-making. State-of-the-art VLMs failed consistently, misclassifying reflections as real objects and mismatching reflected instances to their counterparts; remarkably, providing depth data degraded reasoning performance, implying the models cannot identify incorrect depth in mirror scenes. The authors released the code and data, and note this was accepted to the NeurIPS 2026 education and datasets track.
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