An example might be a simple straight punch. One student may picture a bullet spiraling out of a rifle, generating power and momentum as it travels. Another may imagine his/her hand like Bruce Lee's idea of an iron ball attached to a flexible chain. However, while both analogies may help the student develop form and energy, the point remains that the fist, rotating, travels from point A to point B in the straightest manner possible.
The variance is imagery.
After all, the practitioner of meditation, whether following the tenants of Indian Kundalini or Chinese Tai Chi, are both attempting to reach the same pinnacle of clarity and/or illumination. Just as the Hapkido student and that of Karate are both training in a differing manner but for a similar purpose.
And within these schools, too, each individual finds his/her own way.