User blog comment:JDLover12/Fanmade Mashup Squares 3/@comment-26876874-20170301004812/@comment-25550396-20170301005223

Simple. On Pixlr, I make a duplicate layer of the square. Then, I set the wand tool tolerance to around 40 - 70, whichever removes the outline. I then invert the selection, then cut out everything but the outline on the duplicate layer. (Including the dancer) Only the outline remains. Then, I use the wand tool to select the inside of the dancer's outline. Using the original square layer, I invert the selection and crop out the background.