Starting with your cylinders around arbitrary minor axes, I'm pleased to see that you've gone to some lengths to vary the rate of foreshortening across the set. I have one concern I'll share in a moment, but overall you're doing well - you're applying the error checking correctly here, identifying even small deviations in the alignment.

I'm also pleased to see that you're demonstrating an underlying understanding - whether intentional or just instinctual - of how the shifts from one ellipse to the other (the scale shift where the far end is smaller overall, and the degree shift where the far end is proportionally wider) operate together. It's one of those things I don't mention in the notes, and allow students the chance to figure it out for themselves. Not all students who demonstrate this understanding necessarily register it consciously, but I'll explain it below just to solidify the concept.

Basically, both of these shifts represent the rate of foreshortening - or in other words, just how much of the cylinder's length is visible right there on the page, and how much exists in the "unseen" dimension of depth. It's a visual cue that the viewer's brain will use to understand how that form exists in space, but it can be easy to give the viewer the sense that something is off if the two shifts don't operate roughly together. So if we have the far end get considerably smaller but still maintain roughly the same degree, the viewer will pick up on it, even if they don't understand why it looks off. But it looks like you did this well!

Now, onto the main area for improvement: it seems you're not really employing the ghosting method for your linework here, resulting in side edges that are at times a little wobbly (often very slightly, but enough for me to notice). It's also impacting your ellipses (we use the ghosting method for all our freehanded marks after all), where at times the ellipses come out a little less evenly shaped. Using the ghosting method - which prioritizes a confident execution - as well as executing those marks consistently using your whole arm, from the shoulder, will help. Of course, also be sure to draw through all of your ellipses two full times before lifting your pen. You do this often, but you have a fair number where you don't, or where you do so halfway, but pick up your pen too early to complete the two full turns of the shape.

Continuing onto your cylinders in boxes, your work here is done quite well. This exercise is really all about helping develop students' understanding of how to construct boxes which feature two opposite faces which are proportionally square, regardless of how the form is oriented in space. We do this not by memorizing every possible configuration, but rather by continuing to develop your subconscious understanding of space through repetition, and through analysis (by way of the line extensions).

Where the box challenge's line extensions helped to develop a stronger sense of how to achieve more consistent convergences in our lines, here we add three more lines for each ellipse: the minor axis, and the two contact point lines. In checking how far off these are from converging towards the box's own vanishing points, we can see how far off we were from having the ellipse represent a circle in 3D space, and in turn how far off we were from having the plane that encloses it from representing a square.

In applying those line extensions as directed, I can see that you've been able to identify areas where your approaches were off, so you could adjust that approach and improve from page over page. As it stands now, you should be well equipped to tackle Lesson 6, though there's always room for further improvement.

I'll go ahead and mark this challenge as complete.