diff --git a/src/devtools/mobileharness/fe/v6/angular/app/app.scss b/src/devtools/mobileharness/fe/v6/angular/app/app.scss
index 6794fc756e..afc479de9e 100644
--- a/src/devtools/mobileharness/fe/v6/angular/app/app.scss
+++ b/src/devtools/mobileharness/fe/v6/angular/app/app.scss
@@ -183,6 +183,7 @@ $theme: map.merge(
 @include mat.icon-theme($theme);
 @include mat.menu-theme($theme);
 @include mat.checkbox-theme($theme);
+@include mat.table-theme($theme);
 @include mat.card-theme($theme);
 @include mat.progress-bar-theme($theme);
 @include mat.progress-spinner-theme($theme);
diff --git a/src/devtools/mobileharness/fe/v6/angular/app/shared/services/device_action_service.ts b/src/devtools/mobileharness/fe/v6/angular/app/shared/services/device_action_service.ts
index 3c0ffc7dea..8b0365478d 100644
--- a/src/devtools/mobileharness/fe/v6/angular/app/shared/services/device_action_service.ts
+++ b/src/devtools/mobileharness/fe/v6/angular/app/shared/services/device_action_service.ts
@@ -439,9 +439,12 @@ export class DeviceActionService {
         return this.deviceService.prepareDevice(deviceId, hostName);
       }),
       tap(() => {
-        // TODO: check if we need to refresh the device status, or give a hint that it may take some minutes for it to take effect at the UI side.
+        // It may take around 10 minutes for the device to be prepared.
+        // But when we show this snackbar, device preparation is still in progress,
+        // so there is no need to refresh the device status, and we can NOT tell the user
+        // that the device is prepared successfully yet. Thus we use the following message.
         this.snackBar.showSuccess(
-          `Device ${deviceId} prepared successfully. It may take a few minutes to take effect on the UI side.`,
+          `Device ${deviceId} preparation is in progress. It may take several minutes to take effect on the UI side.`,
         );
       }),
       catchError((err) =>