In the project window double clicking on a Track Picture does not always open the Picture Browser. If the track selection is not synced between the Project Window and MixConsole you can only edit the track selected in the MixConsole from the Project Window.
Open a project with multiple tracks all with Track Pictures.
In Preferences/Project & MixConsole - Sync Selection in Project Window and MixConsole, deselect this option.
In the MixConsole select any track.
In the Project Window select a different track and attempt to change its picture. The browser will not open.
In the Project Window select the same track as the MixConsole and attempt to change its picture. The browser will open.
Neither of these issues was corrected in the 8.5 upgrade. The 2nd one is especially annoying since it ends up changing a Track Picture that you do want to one that you do not want.