This photograph could well have been taken by DC Harries who has used the location elsewhere. The place is 15 & 17 Crescent Road, Llandeilo on the corner of Latimer Road. The distinctive houses with the corrugated iron porch roof still exist in much the same condition today (2022) although No. 17 is more original. No 15 still bears the original name. The front wall railings still remain and are just visible in the photo. See here: https://www.google.com/maps/@51.8838851,-3.9902332,3a,75y,68.63h,85.63t…. There is a DC Harries photograph of WW1 soldiers in the NLW collection that has the same location here: https://torf.llyfrgell.cymru/en/s/dcharries/manifests/view/2/179. Hope this is of interest.