The purpose of the scene is not to explore why the chairman adores Bean. The purpose of the scene is to lend credence to the idea that Bean is an idiot whose employment is not endangered by his idiocy. Because the chairman adores Bean, whatever the reason may be, the chairman will ensure Bean's employment.
It shifts the expectation of the viewer. The movie is tailored to a US crowd, where fear of lack of employment is a more active worry in the mind of the average person. Compared to the UK/Europe, where social welfare tends to not leave people behind.
This does create a slightly different vibe in terms of viewer expectation, how they relate to the character, and where they expect the plot to take them to.
At no point during the entire existence of the Mr Bean TV show was his employment even in focus. The movie's plot required him to have a job which would take him overseas, but it automatically leads to wondering what happens to his job when things go awry.
By ensuring Bean's means of existence (by showing that he is protected by the chairman), the viewer can thus stop worrying about Bean's employment or any threat of being fired, and instead enjoy the idiocy for what it is and live in the moment.