In Logo's Turtle, the pen was a tangible and visible entity which made it easy for kids to comprehend it. In Etoy, the Pen is an invisible, abstract entity whose presence is manifest only in the trails it leaves behind. This runs counter to Morphic principle of directness. Instead, pen methods could be factored into a separate Morph, say PenMorph, that can be manipulated by kids directly to affect size, color, shape, trailstyle and up/down state.
Yes, similar reasoning can go to the drawn trail as well. There were a few attempts to make the drawn line be a polygon.
-- Yoshiki