For the fan, the lines of the fabric maintain the horizontal line that enters the scale in ACL 4.0. Other placements must be spaced and the smoke must overcome the lines on the fabric to form a curve, which is usually possible in ACL 4.6.
Changes in material objects that include linear cues include the following: length, width, duration, fluid amount, volume, centre design, corner design, spacing between objects. You may demonstrate a change in material objects and they will usually retain the directions for a pair of these features.
A diagonal line may be seen as part of a design, but they are rarely able to correct it in their own projects.
Pictures of objects are a good resource for part / whole perception, which people within ACL 4.6 often enjoy. The pictures can be divided into parts along their width and length and then adjusted to fit. This use in a notecard is a sophisticated version of a simple puzzle. Adjustments for depth, height or diagonal lines are unlikely.