His fat, flabby beer gut doesn't help during the motivational speech.
At the end of Series One, a not-unexpected restructuring of Wernham-Hogg sees Brent's boss pose him an unattractive choice: he can accept a promotion to the Corporate board, which would lead to the Slough office being merged with Swindon's and most of his employees ending up unemployed, or he can keep his post in Slough and the Swindon office would then be merged with Slough's, with his workers remaining on the payroll.
Brent, failing to see any dilemma or conflict of loyalty, immediately and delightedly accepts the job and is later bewildered by the failure of those who will be made redundant to be pleased for him.
From this point on Brent spends much of series two trying to attempt to upstage him and prove himself to be the popular and respected boss at every point.
The staff arriving with Godwin during the company merger also quickly grow to disrespect and, to some extent, humiliate him.
Much of the comedy of the series centres on Brent's many idiosyncrasies, hypocrisies, self-delusions and overt self-promotion.