diff --git a/crates/ui-egui/src/panel_docking.rs b/crates/ui-egui/src/panel_docking.rs
index 87f3583d0..ff39d90cf 100644
--- a/crates/ui-egui/src/panel_docking.rs
+++ b/crates/ui-egui/src/panel_docking.rs
@@ -271,8 +271,25 @@ pub(crate) fn showing(ui: &UiState, panel: &str) -> bool {
 }
 
 /// Can either panel that uses row thumbnails be seen, including in a floating window or flyout?
-fn thumbnail_panel_showing(ui: &UiState) -> bool {
-    ui.dock && ui.screen_mode < 3 && (showing(ui, "layers") || showing(ui, "links"))
+/// An iconic group's open flyout is named for the icon that opened it; its active tab can differ.
+fn thumbnail_panel_showing(ui: &UiState, ctx: &egui::Context) -> bool {
+    if !ui.dock || ui.screen_mode >= 3 {
+        return false;
+    }
+    let layout = layout_of(ui);
+    let regular = ["layers", "links"]
+        .iter()
+        .any(|panel| !in_iconic_column(&layout, panel) && layout.panel_state(&(*panel).to_string()) == craft_ui::docking::PanelState::Front);
+    let flyout = craft_ui::docking::flyout::<String>(ctx, area_id());
+    let iconic = flyout.as_ref().and_then(|anchor| {
+        dock_columns(&layout)
+            .into_iter()
+            .filter(|column| column.iconic)
+            .flat_map(|column| &column.groups)
+            .find(|group| group.panels.contains(anchor))
+            .and_then(|group| group.active_panel())
+    });
+    regular || iconic.is_some_and(|panel| matches!(panel.as_str(), "layers" | "links"))
 }
 
 /// Where a panel with no other destination goes: a panel of the first expanded dock column,
@@ -1178,7 +1195,7 @@ pub(crate) fn show(app: &mut VectorcraftApp, ui: &mut egui::Ui) {
         app.open_dropped_files(window.dropped, None, shift);
     }
     forward_keys(app, &ctx, output.forwarded_events, output.forwarded_modifiers);
-    if !thumbnail_panel_showing(&app.ui) {
+    if !thumbnail_panel_showing(&app.ui, &ctx) {
         // No panel can ask for these rows again this pass. Keep the cache of open documents, but
         // discard worker jobs queued behind the one already rendering.
         crate::panels::layers::show_thumbs_of(None);
diff --git a/crates/ui-egui/src/panel_docking/tests.rs b/crates/ui-egui/src/panel_docking/tests.rs
index 3afb41f96..60b59a2a8 100644
--- a/crates/ui-egui/src/panel_docking/tests.rs
+++ b/crates/ui-egui/src/panel_docking/tests.rs
@@ -165,19 +165,46 @@ fn a_tab_dragged_out_floats_and_comes_back_where_it_was_after_its_window_closes(
 fn thumbnail_work_is_needed_only_while_layers_or_links_can_be_seen() {
     let mut h = Harness::new();
     h.app.run("window.panel", json!({"panel": "layers"})).unwrap();
-    assert!(thumbnail_panel_showing(&h.app.ui));
+    assert!(thumbnail_panel_showing(&h.app.ui, &h.ctx));
     h.app.ui.dock = false;
-    assert!(!thumbnail_panel_showing(&h.app.ui), "Tab hides every panel");
+    assert!(!thumbnail_panel_showing(&h.app.ui, &h.ctx), "Tab hides every panel");
     h.app.ui.dock = true;
     h.app.ui.screen_mode = 3;
-    assert!(!thumbnail_panel_showing(&h.app.ui), "presentation mode hides panels");
+    assert!(!thumbnail_panel_showing(&h.app.ui, &h.ctx), "presentation mode hides panels");
     h.app.ui.screen_mode = 0;
     h.app.run("window.panel.float", json!({"panel": "layers"})).unwrap();
-    assert!(thumbnail_panel_showing(&h.app.ui), "a floating Layers panel still needs thumbnails");
+    assert!(thumbnail_panel_showing(&h.app.ui, &h.ctx), "a floating Layers panel still needs thumbnails");
     h.app.run("window.panel", json!({"panel": "layers", "toggle": true})).unwrap();
-    assert!(!thumbnail_panel_showing(&h.app.ui));
+    assert!(!thumbnail_panel_showing(&h.app.ui, &h.ctx));
     h.app.run("window.panel", json!({"panel": "links"})).unwrap();
-    assert!(thumbnail_panel_showing(&h.app.ui), "the Links flyout also uses row thumbnails");
+    h.frame(vec![]);
+    assert!(thumbnail_panel_showing(&h.app.ui, &h.ctx), "the Links flyout also uses row thumbnails");
+}
+
+#[test]
+fn a_collapsed_dock_uses_the_flyouts_active_tab_for_thumbnail_work() {
+    let mut h = Harness::new();
+    h.app.run("window.collapseDock", json!({"collapsed": true})).unwrap();
+    // A customized layout keeps the group's active tab independent of the icon that opened it.
+    h.app.ui.docking = Some(layout_of(&h.app.ui));
+    h.app.run("window.panel", json!({"panel": "properties"})).unwrap();
+    h.frame(vec![]);
+    assert!(!thumbnail_panel_showing(&h.app.ui, &h.ctx), "Properties does not use row thumbnails");
+    // A tab press emits Activate without revealing a different flyout anchor.
+    gesture(&mut h.app, Action::Activate { panel: "layers".into() }).unwrap();
+    h.frame(vec![]);
+    assert_eq!(h.app.ui.open_panel.as_deref(), Some("properties"), "the flyout is still named for its opening icon");
+    assert!(thumbnail_panel_showing(&h.app.ui, &h.ctx), "the active Layers tab keeps thumbnail jobs");
+    gesture(&mut h.app, Action::Activate { panel: "properties".into() }).unwrap();
+    h.frame(vec![]);
+    assert!(!thumbnail_panel_showing(&h.app.ui, &h.ctx), "returning to Properties drops hidden Layers jobs");
+    h.app.run("window.panel", json!({"panel": "layers"})).unwrap();
+    h.frame(vec![]);
+    assert!(thumbnail_panel_showing(&h.app.ui, &h.ctx));
+    gesture(&mut h.app, Action::Activate { panel: "properties".into() }).unwrap();
+    h.frame(vec![]);
+    assert_eq!(h.app.ui.open_panel.as_deref(), Some("layers"));
+    assert!(!thumbnail_panel_showing(&h.app.ui, &h.ctx), "a Properties tab under the Layers icon does not need thumbnails");
 }
 
 /// A Character field shortcut with the Character panel in front of its floating window brings