when i looked at the google cache, it seemed the images from the original author were missing, unless they were trying to say the image without the text was the original....if thats the case, then yeah its pretty clear it's copied.....when i took graphic design in college, i was always stunned by the amount of work that people clearly copied directly from someone and then called it their own by changing a few things around. I was always disappointed that the professors never addressed copyright stuff.
that being said, I own quite a few El Jeffe posters and will continue to buy the ones I like, copied or not.