Theguardian_ It’s hard to be objective about an artist you like as a person. I recently met the painter Jonathan Yeo – whose portrait of King Charles has been unveiled in a storm of crimson hype – on a radio show and was instantly charmed. It’s easy to see why famous people enjoy being portrayed by Yeo. He’s intelligent, relaxed, unassuming. We talked about a studio visit. But then I had a look at his works online and cringed. And that was before I saw this right royal banality.

Yeo’s portrait of the king is replete with all his vices. It is technically superficial and unfelt. There’s no insight into the king’s personality here, just a weird allegory about a monarch butterfly that Yeo says is a symbol of his metamorphosis from prince to king.

Nice flattery. So it’s no surprise King Charles is said to be pleased with his first official portrait since being crowned. As he courageously copes with cancer, who’d begrudge any pleasure this glowing red homage gives good old King Charles? But the pleasing effect of joy and uplift as Charles’s red military uniform melds with a pinkish psychedelic splurge is bought at the price of any genuine artistic perceptiveness or purpose.

Yeo’s art is formulaic and this one follows the formula. He does a pedantic study of someone’s features then – daringly! – collides this staid depiction with a free burst of lurid abstract wallpaper. He did Cara Delevingne in a vague subaqua setting and Taron Egerton in purple and pink rain. To me this is an evasion of actual portraiture which is based on acute, hard observation.

Royalists are never going to want portraits that look at their idols too astutely. Only one great artist in recent times has been allowed near a royal head: Lucian Freud’s searching, cruelly honest portrait of Queen Elizabeth II will never be loved by sentimentalists because it dares to treat the regal personage as just another person. And to be fair, Yeo too has seen Charles in the same way he sees everyone – blandly. I would say his portrayal of that kindly face adds nothing to what we see of Charles in photos and TV images, except that isn’t fair to photographers and camera people who often capture awkward, complex moments in the royal interaction with reality. Even the deferential coverage of the accession gave us those less than jolly glimpses of Charles infuriated by a pen.

It’s tempting to laugh at this painting, but if you care about art it’s a bit sad too. Yeo seems to be saying that painting itself is just a cheery bit of fakery and razzle dazzle. Who cares about truth when you can beautify? A serious portrait would look hard and long at Charles (or anyone), not combine facile pseudo-portraiture with the cheery serotonin of random colour. We all know the king is more complex than this. The king knows he is more complex than this. It is a masterpiece of shallowness by an artist so ludicrously upbeat he should be called Jonathan Yo!