When the video for crossing the lake on the ferryman's boat finishes the game briefly displays the area you just left (the other pier with the ferryman holding out his hand) before loading the right area.
Ubuntu 9.04 amd64, ScummVM svn42646, RtZ CD/DOS/English v1.2
I think that this is what the original did. Could be wrong though, more information is needed here in order to determine if this is a bug in the original or in ScummVM
This could be an artifact of the palette bug (which is also in the original). Probably the palette should be all black before loading the new area.
It makes sense to move it to Wiki then.
This bugreport has been moved to Wiki to relevant Engine/TODO page. When the bug will be resolved, an appropriate message will be posted here and the bugreport link removed from Wiki