There are 2 useful pointers about him that stand out from his otherwise generic uniform. The first is the Royal Welsh Fusiliers cap badge and the second it the belt. It is a 1914 pattern leather belt rather than the usual 1908 webbing belt. Such was the demand for equipment that the Army decided to order a stand in webbing set made of leather as they could not manufacture or import enough of the 1908 pattern one. As your relative is wearing the very same belt it is likely that the photo is taken in 1915 or possibly 1916. Perhaps it is a studio photo of him in his new uniform after enlistment?
I hope that helps.
Thank you so much. After the speculation on here yesterday about the photo I messaged my elderly auntie last night who assured me that the photograph of her dad I posted is the same as the one in a picture frame in her living room!! Heather on Ancestry who posted out to me the 2 photos is the granddaughter of his older sister Mary, we are DNA related and are 2nd cousins. I was also sent the photo by email in 1999 by his son, my uncle, together with a copy of his birth certificate.
Auntie Dilys said she thought her dad had joined up at 17 years of age by which time his father was deceased leaving a Widow and a much younger brother. Perhaps he got the photo taken as a gift for his mother but that's just a fanciful idea on my part.