When creating a block from a drawing, the entire current drawing will be used as the block. The command will add some attributes to the drawing. After the command is finished, you will want to use the Create Slide command to create a slide for the block.
If you select to points, will be asked to select point/s. If you select to the Edges, will see following.
Once selected shape, will be asked to draw edges.
Command is then complete. (Doesn't ask you to save it?)