Document how paris_icc_exif_xmp.avif was created
diff --git a/tests/data/README.md b/tests/data/README.md
index 4044f84..b9d9420 100644
--- a/tests/data/README.md
+++ b/tests/data/README.md
@@ -101,6 +101,14 @@
| 2 | 0xffe1 APP1 | 34 | `Exif..II*......................` |
| | | | ... |
+### File [paris_icc_exif_xmp.avif](paris_icc_exif_xmp.avif)
+
+![](paris_icc_exif_xmp.avif)
+
+License: [same as libavif](https://github.com/AOMediaCodec/libavif/blob/main/LICENSE)
+
+Source: Encoded from `paris_icc_exif_xmp.png` using `avifenc -s 10` at commit ed52c1b.
+
## Grid
### File [sofa_grid1x5_420.avif](sofa_grid1x5_420.avif)