That imaginary audience is always looking over his shoulder, applauding a good hit, chuckling over allusions to the last bit of scandal, and ridiculing any extravagance tending to romance or sentimentalism.
The limitations imposed by such a condition are obvious.

As men of taste, Pope's friends would make their bow to the recognized authorities.

They would praise _Paradise Lost_, but a new Milton would be as much out of place with them as the real Milton at the court of Charles II.

They would really prefer to have his verses tagged by Dryden, or the Samson polished by Pope.

They would have ridiculed Wordsworth's mysticism or Shelley's idealism, as they laughed at the religious "enthusiasm" of Law or Wesley, or the metaphysical subtleties of Berkeley and Hume.