Starting with your cylinders around arbitrary minor axes, you were quite mindful of the execution of each individual mark, resulting in smooth, clean strokes for the edges and ellipses that were for the most part quite evenly shaped. There were a few cases where you didn't draw through your ellipses (you should be drawing through each ellipse you freehand in this course), but you largely did well.

I'm also pleased to see that you were careful in identifying the correct minor axes for your ellipses, as this helped you continue to move closer and closer to executing those ellipses with considerable accuracy.

Lastly, for the most part you appear to have been aware (whether consciously or intuitively) of the relationship between the scale shift between the ends of the ellipses (where the far one is smaller and the closer one is larger) and the degree shift (where the far ellipse is wider and the closer ellipse is smaller). This is something I leave for students to discover on their own throughout this challenge, and you've generally done a good job of avoiding mixing that up. As both of these shifts suggest whether the cylinder is longer or shorter (a more significant shift in either suggesting more distance between them, therefore a longer cylinder), it is easy to end up in a situation where we have a more significant shift in one, but not in the other, resulting in a contradiction. For the most part you did a good job of keeping these consistent.

Continuing onto your cylinders in boxes, I did admittedly find that while your line quality wasn't bad, there are signs that you weren't as consistent in executing your lines with confidence and applying the ghosting method here. This resulted in lines that weren't wobbly, but that did feel just a little bit stiff and hesitant. We are of course talking about very, very minor issues, the kinds of things that I've become attuned to finding when it comes to determining whether or not a student is executing their marks with confidence, or more slowly and carefully.

Another issue I did notice, which is actually quite significant, is that while in the first section you demonstrated a clear awareness of how the minor axis of the ellipses ought to align down the center of the cylinder, in this section it appears to have slipped your mind. In this image you had lines marked out for your ellipses' minor axes, but the ellipses weren't aligned to them at all. I drew minor axes on top of them in red, and then drew the actual ellipse that would align to it (along with the degree that would fit within your box's plane).

The reason doing this correctly is so important is that this exercise is entirely focused around developing your ability to draw boxes that are proportionally square on two opposite sides. For this, we use the cylinders as a sort of error-checking method, similarly to how in the box challenge we used line extensions. In this case we add the minor axis and contact points' lines for each ellipse.

The ellipse's lines will only line up to the vanishing points of the box if those ellipses actually represent circles in 3D space that sit on the surface of the box. This means that if those lines do converge towards the same vanishing points, then the ellipse represents a circle, and therefore the plane that encloses it must also be a square. Just as with the box challenge, we draw a page of these, do our corrections/analysis, then identify ways in which we can adjust our approach to improve how closely those lines all converge. As we do this repeatedly, we gradually improve our intuitive grasp of how to draw boxes that are proportionally square on two opposite sides. Of course for this to work, we need to make sure we're actually identifying the minor axis correctly.

Now, to ensure you understand this last concept and take more care to avoid mistakenly drawing your ellipse without considering its true minor axis while doing your line extensions, I'm going to assign another 15 cylinders in boxes. Once those are done, I assume they'll be done quite well (this was an understandable mistake, one where you got distracted as anyone might), and I'll mark this challenge as complete at that point.