Formal oil portraits of leaders are not associated with the non-profit sector. We usually associate them with the captains of industry who donate their money to non-profits, or with government officials such as governors and judges. These formally posed paintings hang in corporate boardrooms, country clubs, drawing rooms and state houses. You don't see them at the local food bank, and you don't want to.
This is because the symbolic weight--and cost--of an oil portrait is just too much for charities to bear. The very act of posing for an oil portrait is at odds with the inherent selflessness of the charitable impulse. The portrait's entire purpose is glorification of the individual. Unless you can persuade donors that the portrait's subject is the personification of Faith or Hope or better yet Charity, the donors will wonder how an oil painting advances the organization's mission. I, for one, can't think of how.
Someday the museum trustees will ruefully realize that long after the financial indiscretions are forgotten, everyone will remember the $48,500 portrait. People may even remember the name of the man depicted standing in front of the museum with his suit coat draped over his left shoulder (a silly pose to begin with, in my opinion). It will not be a pleasant realization to a trustee of donated funds.
Here's my advice to museum trustees who might be tempted to honor charity executives with an expensive oil portrait: Try Photoshop--it's cheaper.