This is how people knitted in Sweden before "continental" arrived. The technique is called "tvåändsstickning" (two strands knitting) which even to me looks strange in print - and it's my mother tongue!
You knit with two strands, both held in right hand and twisted between each stitch. Garments knitted this way are thick and not very elastic, which makes them perfect when it's cold and windy.
The right side looks more or less like ordinary knitting, but the wrong side is completely different: it looks like rows of cords. A nice thing is that relief patterns get deeper than in ordinary knitting. I think you can see these things fairly clearly in the picture.