What does it mean that the pen tip flies like a phoenix and flows like a dragon?

The pen tip shines like a phoenix dance and flows like a dragon, describing the vigorous and lively brushwork of calligraphy. Calligraphy is an artistic expression of the unique beauty of words in China and neighboring countries and regions deeply influenced by China culture. Including China calligraphy, Mongolian calligraphy, Arabic calligraphy and English calligraphy. Its China calligraphy is a unique traditional Chinese character art in China.