The direction in which the image should tend to slide. Legal values are
\fIrandom\fP (meaning pick one), \fIup\fP, \fIleft\fP, \fIright\fP,
\fIdown\fP, \fIupleft\fP, \fIdownleft\fP, \fIupright\fP, \fIdownright\fP,
-\fIshuffle\fP (meaning perfer no particular direction), \fIin\fP (meaning
+\fIshuffle\fP (meaning prefer no particular direction), \fIin\fP (meaning
move things toward the center), \fIout\fP (meaning move things away
from the center), \fImelt\fP (meaning melt straight
downward), \fIstretch\fP (meaning stretch the screen downward),