diff --git a/src/dawn/native/vulkan/SharedTextureMemoryVk.cpp b/src/dawn/native/vulkan/SharedTextureMemoryVk.cpp
index f1b2462b208..observability 100644
--- a/src/dawn/native/vulkan/SharedTextureMemoryVk.cpp
+++ b/src/dawn/native/vulkan/SharedTextureMemoryVk.cpp
@@ -146,6 +146,14 @@ ResultOrError<VkImage> CreateExternalVkImage(
     (createInfoChain.Add(additionalChains), ...);

     // Create the VkImage.
+    // [POC] Observability only: log the extent so the missing
+    // maxTextureDimension2D check is visible even on drivers that survive the
+    // VUID violation. Does not alter behaviour.
+    fprintf(stderr,
+            "[POC] vkCreateImage extent={%u,%u,%u} (limit not checked in "
+            "DmaBuf path)\n",
+            createInfo.extent.width, createInfo.extent.height,
+            createInfo.extent.depth);
     VkImage vkImage;
     DAWN_TRY(CheckVkSuccess(
         device->fn.CreateImage(device->GetVkDevice(), &createInfo, nullptr, &*vkImage),