Quoting Mike Volpi on Board membership

 From https://techcrunch.com/2020/02/12/effective-board-members-create-value-for-startups:

One of the analogies I often use for the role of a board is that of being a “mirror” to the management team. Entrepreneurs, by their nature, live on a roller-coaster ride that is matching their startup’s journey. Their perception of the business is often an amplification of the current state of the business. The highs are often more optimistic than the business might really deserve and the lows are often much lower than they should be. The board should reflect a snapshot of the reality of the business. All businesses, both the most successful and the somewhat troubled, involve a lot of sausage-making. There are aspects that are not working well that shouldn’t be brushed aside or ignored, but should be focal points of improvement. Conversely, when things aren’t going well, entrepreneurs can often be too critical of their own business.

By placing things in the context of other experiences, the board member should aid the entrepreneurs in “normalizing” the state of the company.