The idioms mean the same thing. They refer to a situation where someone is reading something, looking at something or commenting on a particular action that has occurred. They do not know exactly who was the originator of what they are commenting on, but because they know the characteristics and past actions of someone, they believe it must be them that did it. A mother with three children walks into a room. She sees broken dishes on the floor but no one is in the room. Of the three children, John is destructive, sloppy and self-centered. The mother says "This has John's name written all over it." she knows it must have been John who did it. A boss is reading a report supposedly submitted by Allen. The boss knows that Allen is at best average, but the report is outstanding. The boss also knows that Allen is good friends with Fiona who is the best worker at the company. The boss comments to Allen "Allen, I know you gave me this report, but it has Fiona written all over it."