Fix visual regression

Author: florianduros

res/css/structures/_ThreadsActivityCentre.pcss

@@ -22,15 +22,19 @@
 
     &.expanded {
         /* align with settings icon */
-        margin-left: 22px;
+        margin-left: 21px;
 
+        /** modify internal css of the compound component
+         * Dirty but we need to add the `Threads` label into the indicator icon
+         **/
         & > div {
             display: flex;
         }
 
         & .mx_ThreadsActivityCentreButton_Icon {
             /* align with settings label */
             margin-right: 14px;
+            /* required to set the icon width when into a flex container */
             min-width: 24px;
         }