You make my day as this is the first question I can answer on this board :lol:
Its a simple tubequilt. You sew for example two 2" stripes together with a 1/4" seam, iron to the dark side and put an 3.5" stripe (on the picture the floral) right sides together on top of it. Sew both sides with an 1/4" seam and cut triangles with an 45degree ruler. Four of those give you a block.
There is a tutorial on youtube, just google for tubequilt.
Granny