If it is Lee Oswald's body, then they dressed him in Lovelady's red plaid shirt. Oswald's arrest photos show Lee wearing a brown grainy shirt. Groden's book "TKOAP" shows Lovelady wearing his red plaid shirt. The Hughes film shows it to be a read shirt. Altgens photo #6 shows the plaid design. Lovelady's head - Lovelady's clothes.
Bill Miller
It's a bit curious that Oswald, as shown in photos of him in custody, has his shirt unbuttoned, in the same manner, down to the same button, as the figure on the doorstep.
Look closely at Oswald's shirt and you also see lines, similar to those you highlighted, running through it.
Perhaps an overlay on Oswald's shirt would show similar results?