Art is a reflection of reality. So, yeah, they’re pretty accurate. Painful to look at, but accurate.
What shocks you about the Obama portraits is not the actual paintings, which reflect poorly on how the artist sees the Presidency, but the fact that the former President took his acknowledgement for posterity so lightly. He allowed himself to be made into a joke.
But what's even more shocking, is that reflects exactly what his Presidency was--an 8-year joke on the United States. It's actually a brutally honest painting.