The Mantra Mandala is beautifully represented with Vajra in the middle and the mantra is repeated around it.
The mantra mandala gives the wisdom of enlightenment.
Mantra and Mandala
A mantra is like a magic spell. A series of syllables that have an effect on the mind. They often have only a vague symbolic meaning, or no meaning at all, but their effectiveness is an energetic or vibrational effect.
A Mandala is like a visual mantra. It often symbolically symbolizes the environment around the deity who resides in the center. This is analogous to you dwelling in the center of your experience and your environment is an extension of your sense consciousnesses which vibrate out from the center and back in.