This excellent poem represents the way that Indians have adapted and used English for their own purposes, giving it a distinct Indian flavour, even though officially it is still the same language. He achieves this through personifying the English spoken in India as a mistress, a female character who bears unmistakable characteristics of both England and India. Consider the following mish-mash of culture in the description of this "mistress" and how ridiculous an image it creates in our head:
Despite this she is vain,
Flashes her bangles and her tinsel;
Wears heels even though he feet
Are smeared up to the ankle with henna...
Note the reference to hallmarks of Indian culture such as "bangles" and "henna" and how these are put together with characteristics of English culture, such as "tinsel" and "heels." The visual image the poem creates of a woman wearing heels but also covered in henna is ridiculous, and we can see how he is choosing to poke gentle fun at the way that Indians have taken the English language and added so much of their own culture to it.