diff --git a/tools/chatgui/tests/test_desktop_commands.cpp b/tools/chatgui/tests/test_desktop_commands.cpp
index a3ffdc2dc..72b7fe54f 100644
--- a/tools/chatgui/tests/test_desktop_commands.cpp
+++ b/tools/chatgui/tests/test_desktop_commands.cpp
@@ -329,6 +329,12 @@ private slots:
         const QString photo = directory.filePath("photo.png");
         QImage image(32, 24, QImage::Format_RGB32); image.fill(Qt::green); QVERIFY(image.save(photo));
         const auto logger = qScopeGuard([] { debug_disable_file_output(); });
+        const auto diagnostics = qScopeGuard([&] {
+            if (QTest::currentTestFailed()) {
+                directory.setAutoRemove(false);
+                DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "Media geometry fixture failed; diagnostics: %s", qPrintable(log));
+            }
+        });
         auto findWindow = [](const QString& name) -> QWidget* {
             for (auto* widget : QApplication::topLevelWidgets())
                 if (widget->objectName() == name && widget->isVisible()) return widget;
@@ -341,6 +347,7 @@ private slots:
             auto* node = window.utunNode();
             if (!node || !node->isRunning()) directory.setAutoRemove(false);
             QVERIFY2(node && node->isRunning(), qPrintable(log)); QTRY_VERIFY(db.isOpen());
+            debug_set_category_level(DEBUG_CATEGORY_GENERAL, DEBUG_LEVEL_DEBUG);
             QVERIFY(QMetaObject::invokeMethod(&window, "openImage", Q_ARG(QString, photo)));
             auto* viewer = findWindow("chatImageViewer"); QVERIFY(viewer);
             if (!stage) {
@@ -355,6 +362,11 @@ private slots:
                 QCOMPARE(viewer->isFullScreen(), fullscreen);
             } else {
                 QCOMPARE(viewer->screen(), window.screen());
+                const QRect area = window.screen()->availableGeometry(), actual = viewer->normalGeometry();
+                const QMargins margins = viewer->windowHandle()->frameMargins();
+                DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "Media fallback: area=%d,%d %dx%d normal=%d,%d %dx%d frame=%d,%d,%d,%d state=%d",
+                           area.x(), area.y(), area.width(), area.height(), actual.x(), actual.y(), actual.width(), actual.height(),
+                           margins.left(), margins.top(), margins.right(), margins.bottom(), int(viewer->windowState()));
                 QVERIFY(window.screen()->availableGeometry().contains(viewer->normalGeometry()));
                 QVERIFY(!viewer->isFullScreen());
             }