The T-shirt, which shows a colourful picture of seven of the Queen's dogs, was inspired by a painting that belongs to the Queen and currently hangs in her private quarters in Buckingham Palace.
British artist Cindy Lass is the mastermind behind the endearing T-shirt and chatted to HELLO! Online about her royal piece.
"I first did a painting of the Queen's corgis," said Cindy about the 2006 commission. "I was asked to do that and I delivered it to the palace for her 80th birthday."
Years later, the talented artist transferred the portrait into a T-shirt for Prince George, knowing that the 87-year-old reigning monarch had a love for the special breed of dogs.
"I thought I'd do a cushion for Her Majesty of the corgis with a crown on the back of it," said Cindy. "And when I was sending it in, I had done a sample for a one-year-old T-shirt and I thought it would be nice for her great-grandson to have so I sent a sample with it.
In return, Cindy received a personalised thank you note written on behalf of the Queen, saying that it was "kind to enclose the T-shirt" and she "greatly appreciated" the gift. Her Majesty also thanked the artist for her "continual loyalty and support."
"When I got the letter back to say that Her Majesty had passed it on to him, it was very sweet," said Cindy. "My mum saw the letter with the heading Buckingham Palace, saying it was going to be passed onto Prince George of Cambridge, and she said, 'Oh my God, the future King's going to be wearing one of your designs.' She was really proud. I felt her pride.
"The fact is, is that it made Her Majesty happy to give it to her great-grandson, so it's lovely to be part of that chain."
At the time of her commission, Cindy was given a snapshot of the Queen's dogs to use as a basis for the painting.
"There was one photo with all her dogs in, the dorgis as well," said Cindy. "I didn't really know at the time what they were, but the lady-in-waiting said it was a combination of a daschund having a relationship with a corgi. The main five are corgis and the others are called dorgis.
"The ladies-in-waiting said that the Queen loves the painting. It makes her smile and she's happy. I like to make art accessible and it's lovely to know that my art makes people smile."
Does Cindy have plans to create another T-shirt for Prince George?
"Maybe when he gets older I might design one that's more 'shi shi' for him," laughed Cindy. "As for a painting, I most probably will. But everything with my art is inspired by something. It depends on what I feel because I'm quite psychic and as Prince George grows up, I'll be able to see what he's like as a young little lad and I'll see how I feel.
"If I actually met him I could get a vibe and say exactly how his feelings would be, his strengths in his life. Lots of people have different gifts and apparently that's one of the gifts I have."
Cindy is currently illustrating a corgi book and will be travelling to Sydney where one of her tree paintings will be exhibited in a museum.
Photograph of the T-shirt taken by Laraine Krantz for You Love Cindy.