This enlargement shows one of the soldiers who was lying on the ground in the front row.
The shoulder titles, so often difficult to see in photographs, are now reasonably clear. The letters "RSF" (Royal Scots Fusiliers) are in metal below a metal grenade badge, a symbol of all fusilier regiments, and can be made out in the original photograph.
The grenade in a different form is also used as a badge on the Glengarry.
The soldier has an interesting patch on his shoulder which has the number "12". It may mean that he is in the 12th Battalion of the regiment, but this battalion was raised in Egypt in 1917, and made up of men from the Ayrshire Yeomanry and Lanarkshire Yeomanry, whilst the photograph looks rather as though it was taken in the UK. The badge may instead indicate the 12th Reserve Brigade, which had men from the 9th Bn Royal Scots Fusiliers, and was based at Inverkeithing, Fife. Several other soldiers in the main photograph also have the "12" patch.