EXIF orientation not normalized: The image orientation processed by the model differs from how humans view it, introducing interpretation bias.

PNG tRNS not explicitly flattened before converting to RGB: After conversion, transparent/semi-transparent pixels are rendered unexpectedly, making otherwise subtle overlay elements visible and distorting the input content. (This attack is similar to AlphaDog: RGBA handling is already correct in vLLM, but since tRNS permits RGB images, the correct processing path isn't taken.)

Pillow only loads the first frame when loading APNG or GIF files.

Root cause:
- Rotation: After opening an image, ImageOps.exif_transpose is not called to normalize EXIF orientation.
- Transparency: Only RGBA to RGB is flattened with a background; PNGs carrying tRNS in P/L/RGB + tRNS and other non-RGBA modes take the image.convert("RGB") path, which implicitly discards/remaps transparency semantics.