Your dog on a t-shirt, drawn — not printed: how the photo door works
A photo of a dog on a t-shirt is usually a photo of a dog on a t-shirt: a rectangle of pixels, a little blurry, the colours of a cotton print. This is the other thing. You give the shop a photograph and it gives you back a drawing — the same dog, in ink dots, that could have been done by hand by someone who had a lot of time and loved him.
This is Jokker. He is a Cardigan corgi and he belongs to the people who run this shop, which is why he is the example.

What the photo door does
Tap Use a photo and give it a picture. The machine cuts the subject out of the background first — the forest, the sofa, the person holding him are gone — and then redraws what is left in the shop's own dots: dense where the coat is dark, open where it is white, the paper showing through as the blaze down his nose. It is not a filter over the photograph. It is a drawing that used the photograph to know what Jokker looks like.
You get three takes. The first is on the shirt in about ten seconds, and "Another one" turns to the next. They are the same dog from the same picture, drawn three times, and one of them will have caught his face the way you see it.

The photo that works
We tried six of him before this one, so here is what we learned, for free.
Crop to the animal before you upload. The drawing is made from what is in the frame, so a dog small in a wide landscape comes out small and soft. The picture that worked was a tight crop — ears, face, chest — from a photo where he was running up a path with his tongue out. The full photo had his feet in long grass, and the cut-out took the grass with them.
Nothing in front of him, nothing held. A toy under his chin, a hand on his back, a branch across his nose all come along into the drawing. The cleanest results had the dog alone against something soft and far away: snow, a path, a blurred wood.
The face in focus, looking somewhere. Straight at the camera or clearly away — both draw well. The eyes are what the dots have to get right, and a photo where they are sharp is a drawing where they are.

On the shirt
The drawing is printed in black ink on white, natural, sand, light blue and sport grey; on the dark shirts it goes in bone with a soft field of dots under it, which suits a drawing with solid shapes more than a soft tonal one like a coat — if your dog is mostly dark, a light shirt is the honest choice.

A Gildan tee in four cuts, €34.90, printed to order in Germany and posted with tracking; ten percent off the second shirt in the same order, which is how a dog ends up on two people. When you buy it, the drawing is yours and nobody else's — nobody is ever offered your dog.
One line for the people who worry about this: your photograph is used to make the drawing and for nothing else. It is deleted after thirty days, and the Privacy Notice says so in writing.
Try it with yours. Drawing is free — if the first three takes are not him, crop tighter and ask again.