Group of soldiers - help please Y&L I think

[Claire64]

Well done Jim.  I've marked Winfield Crawshaw on the photograph.  He was born in 1896.

I'm intrigued - how can you tell who's an NCO?
How can you tell what is an economy tunic?
How can you tell who's the Lance Cpl
What is the significance of the lanyards, and the shoulders they are worn on?
Many thanks for your help, I appreciate it.

[jim1]

L/Cpl. = 1 stripe.
Cpl. = 2 stripes.
Economy tunics don't have the pleated top pockets.
There is no significance in the lanyards as they worn by all sorts.
Having said that they were worn on the left shoulder & not the right until the mid 20's.
Looks like the Cpl. was ahead of his time or as he's hiding his right hand had an injury preventing him from using it.
I thought your man was the one in front. The one you circled was my 2nd. choice... honest.

[Claire64]

Well I am very impressed with your powers of deduction Jim!!
Here's a photo of Winfield.
Many thanks to you all for your input.
His father died in the March of 1917, and his mother had two sons in the War, one of whom returned, one who did not. I have the letter Winfield's mother wrote to the War Office asking is her son, MIA, had been found yet.  All these individual stories, so tragic. 

[Claire64]

Forgive my ignorance...Is a Corporal also an NCO?  I know Lance Cpl is.

[jim1]

Yes. NCO = Non-Commissioned Officer.
You'll notice the lad sitting on the duck board on the right has black cloth on his 2nd. button showing a loss of a close family member. Another tragic story.