The image lengths are 2/5 of the preimage length.
side JN for instance is 2/5 as long compared to corresponding side JK.
Recall that similar figures have the same shape, but different sizes. By "same shape", it means the angle measures are not changed.
For example, triangle JKL and triangle JNO can both be equilateral triangles (each angle is 60°) but of different sizes. Another example could be each triangle has angle measures of 45°, 45°, 90°.
Extra info: If two triangles are congruent, then they are automatically similar. The same is not true the other way around. Congruent triangles have a scale factor of 1.