The top icon represents a sketch with "regions".
The sketch icon will be converted to this if you make a feature from the sketch and within the feature's property manager you select a portion of the sketch in the "Selected Contours" input area.
The bottom icon with the asterisk instead of pencil??? Someone else please?
The bottom icon with the asterisk instead of pencil = 2016 Sketch icon
SW 2016 does not have the pencil for sketching. That icon is a regular sketch.