"If there is a format for success for Will and Kate, it is simply that they look happy," Ingrid Seward wrote in The Sun.
She said Prince William and Middleton appear as a "double act" at charity events and public appearances, working the crowd together.
"During their tour of North America they put this to great use, laughing and exchanging loving glances and the occasional tactile moment," Seward wrote.
The opposite was true of Princess Diana and Prince Charles, she said, as Charles "would bristle at the adulation his wife was receiving."
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