Starting with the arrows, these are definitely flowing very fluidly through space. One thing to keep in mind however is that as we move farther back, the spacing between our zigzagging sections will continue to compress - just like perspective makes the ribbon itself narrower, it also impacts the negative spacing similarly. So in situations like this one, the ribbon itself gets thinner but the spacing remains the same, resulting in a visual contradiction that undermines the illusion that we're looking at something three dimensional.

For your organic forms with contour curves, one thing that caught my eye is that while you're definitely making an effort to stick to simple sausage forms as described in this section of the instructions, they're not quite correct. Where the ends ought to be spherical, yours are more stretched out, causing them to swell out more through their midsection. It's not far off, but it does result more of a "fat" impression that will be a bit problematic when we use these in constructions later on.

The contour ellipses however are looking good - evenly shaped, and while there's some minor issues with them not fitting entirely snugly between the edges of the sausage forms, you're getting close and ever-improving. Your contour curves are more accurate, and are similarly well done.

I think you've done a pretty good job with your texture analyses, specifically in conveying your understanding of the clear focus on shadow shapes over outlines, and this improves as you push through the different rows of this exercise. You continue to take it further into your dissections, where you're experimenting with all kinds of textures and are doing an excellent job of focusing on capturing them using shadow shapes. There is still some trouble when it comes to actually transitioning from dense to shallow texturing (like in the lizard and dragon skin) - this suggests that you still have a ways to go in terms of understanding how to properly employ implicit texture rather than how you're explicitly enclosing each and every scale, but that is simply something to think about as you continue on.

You've done a pretty good job with your form intersections, though there are definitely places especially with your ellipses where you're going back over your marks in a rather sketchy fashion that you need to get some control over. Drawing through your ellipses is good and proper (ideally just 2 times around the ellipse), but make sure you're applying the ghosting method when adding line weight and don't repeat the stroke over and over. Every mark you put down should be the result of forethought and planning. Line weight should itself never get noticeably thick - it's something to be subtle, just a whisper to the subconscious of the viewer. You've done a better job of this in some of these pages (like your box-only ones), but some of the weight added to your ellipses get really heavy, to the point where it's more like screaming into the viewer's face.

Getting back to the forms, you've done a great job of drawing them such that they feel cohesive and consistent within the same scene. This is the main focus of this exercise - the intersections themselves on the other hand, which you've got a good start with, are something I merely want to introduce to students at this stage. It's a subject we're going to continue to explore as we move forwards through the lessons, as what it introduces is the concept of the relationships these forms have with one another in 3D space. Given that this is at the core of Drawabox as a whole, planting the seed and having students start to think about it right now will have them continuing to develop it as we move forwards.

Studying arrangements of forms in a 3D software won't actually help with what we're trying to do here, at least not all that much. Reason being, if we're looking at the problem solved in front of us, it's easy to rely more on our observational skills to reproduce what we're seeing. By being forced to sort things out in our heads, we're gradually developing our internalized model of 3D space. It's hard, and it's expected to be out of the reach of students right now, but as we continue working through the constructional lessons ahead, it will gradually get easier.

Lastly, your organic intersections are a good start - you are definitely establishing these forms such that they're slumping and sagging against one another in 3D space rather than just being pasted together as flat shapes on a page. Your second page is also a good improvement over the first, where the cast shadows are behaving more naturally and consistently than the first (for example, only having the shadows cast on one side of a given form). One thing to keep in mind with that second page though is that you've got a big stack of sausages where they're resting in parallel with one another. If you think about what might happen if you unfroze time and allowed them to behave in accordance with physics, they'd immediately roll off and tumble to the ground. When doing this exercise, try and arrange the form in a way that would suggest stability - running the sausage forms across one another (perpendicular instead of parallel) would help with this.

So! All in all, you've got some good work here. I'll go ahead and mark this lesson as complete.