“Loading folder …” by Dolphin

Today I am using the file management application “Dolphin 17.12.2-1.1” once more in a session of the desktop environment “XFCE 4.12.1”. I am observing the message “Loading folder …” (together with a moving blue rectangle) in the bottom right corner for a while after I clicked the entry “Personal folder” in the left places widget.

How are the chances to clarify this software behaviour?