Scale factor shows by how much the original model has been multiplied or divided by to get the measurements of the drawing .
In this case the ladybug is 8 mm long but drawing length is 2 cm.
Let’s convert both into the same units
2 cm -20 mm
Original - 8 mm
Painting -20mm
X - scale factor
20 = X * 8
X = 20/8 = 2.5
The ladybug has been multiplied/ enlarged by a scale factor of 2.5 to draw the painting