Notice the darker umbra and the surrounding, somewhat lighter penumbra. Both observations were made at a magnification of 75x. Notice the greatly different image scales in the two sketches despite the use of the same magnification. It's not at all uncommon for observers to depict objects in sketches at apparent magnifications that greatly exceed the magnification actually used with the telescope. This practice sometimes leads the novice to harbor greatly inflated expectations concerning how large an object should appear through a telescope.
Much detail is often visible upon careful inspection of a relatively tiny image.
Notice the limb darkening around the edge of the sun. This effect was an early indication that the sun generates much of its light from deep beneath its apparent surface. Notice also the two 'belts' of sunspots parallel to the solar equator. Sunspots tend to appear at latitudes of greatest differential rotation. The 'sunspot belts' bear a slight resemblance to Jupiter's equatorial cloud belts.