Burns Puppy is intended for puppies right from weaning (when it should be moistened with water) until 6 months of age. The small biscuit size of the Mini variety also makes it suitable for toy-breed adults that benefit from the higher protein and fat levels of the food.
Like virtually all Burns foods, Burns Puppy Mini is a very simple diet based around rice, oats, meat and peas which makes it completely hypoallergenic and suitable for even the most sensitive of puppies. The ingredients are also high quality with chicken meat meal and brown rice forming the food's core.
Although brown rice is a good quality ingredient, you can have too much of a good thing. It is the first ingredient in Burns Puppy Mini, which would be questionable in any premium dog food (where meat should be the first ingredient), but is especially dubious in a puppy food as puppies need more protein and fat to grow and should therefore receive more meat from their diet.
The percentages of the ingredients are not specified but with 3 grains in the top 4 ingredients, Burns Puppy Mini is certainly a grain-heavy diet which doesn't seem to warrant its relatively high price.
Conclusion: A fairly good, natural puppy food but over-priced for what you get.