It’s odd when anyone Royal or celebrity does a hospital visit without a specific reason.
The celebs who go to lift spirits and entertain in costumes and in character make sense.
Someone like Diana and Princess Margaret making private visits to the Lighthouse to comfort and try to cheer up AIDS patients.
Those visits make sense and are also usually kept private at the time.
The head of state or his representatives visiting the injured after disaster or attack makes sense as it’s making sure those victims are heard and seen to be important to the government.
Royals and other celebs doing hospital visits for specific patronage and a specific awareness raising visit also make sense - William with emergency personnel and the people they save, Kate at the Marsden especially after her recent cancer treatment etc.
When abroad the royals’ agenda is set by the government of the home country so a hospital visit would have a specific purpose to the host country.
Random celebs arranging to meet sick kids in a hospital lobby for absolutely no reason at all apart from a photo op is beyond bizarre.