It evokes the image of a king or queen being served by their staff, receiving the best of everything, and having all their needs and desires anticipated and fulfilled.
Here are some examples of how the phrase can be used:
* "My parents spoiled me rotten, I was treated like royalty growing up."
* "The guests at the luxury hotel were treated like royalty, with every whim catered to."
* "He felt like he was being treated like royalty when he was invited to the exclusive party."
The phrase emphasizes the idea of extraordinary attention and pampering, suggesting a level of service that is above and beyond the ordinary. It can be used to describe a variety of situations, from personal experiences to customer service.