The reason for the variations of the character is the different calligraphic styles used by artists and their individual interpretations.
The website Chinese Names illustrates this point by showing four distinct Chinese calligraphic styles for the word love.
In the semi-cursive script style of calligraphic writing, the characters look the most similar to normal handwriting.
Geometric styles like Celtic knots work well and so do calligraphic ornaments.
Of his own work few, if any, examples have reached us; and those attributed with more or less probability to his hand are all representations of Buddhist divinities, showing a somewhat formal and conventional design, with a masterly calligraphic touch and perfect harmony of coloring.