It´s easy to say it wrong, because the pencilling does actually look like lace, doesn´t it?
The reason I think it´s a pullet is that it´s round, pencilled, and full of feathers. The cockerels tend to be lanky, more sparse with the feathers, and they normally have quite a bald patch on the wings where their 'grown-up' feathers will come in. Buff cockerels will grow darker buff, almost chestnut feathers in this area. Partridge cockerels will grow brown feathers in this area, etc... Cockerels also develop the habit of keeping the head up, on watch....the pullets generally are too busy scoffing!
I bought 3 little pullets of about a month old. I knew they were pullets because of the feathering....they are very heavily pencilled and well-feathered. One has a much redder face, but she´s still a she.