Hello glykeria! First of all your questions:

-For the restarting the lessons thingy keep in mind you gotta redo all the lessons you've done up to now so you can keep in mind the previous feedback for each lesson. You don't have to redo the box challenge entirely, but you should do 50 new boxes added to your previous ones at least. So don't forget about that!

-You're not expected to do perfectly on the rotated boxes exercise at this point of the lessons, but since you said you already are at lesson 3 or more I'll answer them!

The horizontal and vertical lines thingy is connected to your other question. In this exercise, to make it easier uncomfortable asks you to place the boxes so close together that the lines that are close to each other are practically parallel. They aren't actually parallel, but they are very close to being parallel. So by replicating the lines that are close to each boxes you get without needing to do any calculation the lines on perspective. Here's an example.

For the second question it's easy to replicate in real life. Try placing 2 boxes very close together like I did on the drawing. They're extremely close right? Now try rotating one of the boxes. You will notice that you can't rotate it! They would get away.

Uncomfortable makes this exercise like this so you can realize that lines that are very close will share the same perspective, so he has to rely on not using perfect cubes for doing this exercise.

That being said like I said this is quite hard, so don't worry if you don't understand it. You can look back to this explanation from time time to time until you understand it if you want! Things will start clicking more and more with time,.

And for the last question what I said earlier. For the next lessons you'll sadly have to redo everything past the box challenge.

:(

Now into your actual critique! Overall you've done a good job, but I have a few things I want to comment on, let's go!:

Starting with your lines you're overall doing a good job at committing to your lines even if they're going to miss the ending dots. Overall though you tend to make your lines a little bit wobbly, so don't forget to draw from the shoulder and try to loosen up a little bit more until they get fully confident and straight. That's your main goal.

Other than that you're doing a great job planning your lines carefully and I can see you approach them on the ghosted planes as well as you did previously. Good job!

Moving onto your ellipses you're also doing a good job on them, they are clean and almost confident, but I can see a little bit of hesitation that ends up making them wobbly at times and making their shapes uneven. Just like with lines try to loosen up more and make sure you give a shot at drawing a bit faster as well. It helps with confidence.

On ghosted in planes you have the same problem, but make sure you focus on confidence here as well. Don't get decieved by the planes, you should approach the ellipses the same way regardless of the form of the planes. Ellipses shape can't change, so only thing you can change about them is how you place them, how tilted they are, how wide they are and how big they are.

Lastly on your funnels sometimes you aren't aligning the ellipses to the minor axis. Make sure you always aim for the ellipses to be cut symmetrically by the middle line even if that means you need to ignore the initial curves.

Finally in your boxes a few things:

-Generally I see you hesitate in your lines more than on the previous exercises. Keep in mind that your first priority with lines is to make them confident and straight regardless if they're on boxes or lines , so focus on that first and don't worry if you need to sacrifice accuracy to achieve it.

Here's one example, top line is a level 1 line, and bottom line is a level 0 line. This is because a confident line will always be better than a wobbly line in these exercises.

-Sometimes you repeat lines that were off. No matter how off a line is do your best not to repeat it, keep going as if it was correct as redrawing them will make the drawing messier and can encourage bad habits.

-On plotted perspective the hatching is a bit rushed. If you do hatching make sure you place the pen at the start of each line in the side of the boxes you're hatching, otherwise they will fray on both ends.

-On rough perspective you seem to have trouble at times keeping height lines perpendicular to the horizon line, and width lines parallel to it. I know it's hard, but make sure you always are aiming for it. You can check if the starting and ending dots are correct or not, and if you find that they aren't you can change them. You can put down as many dots as you want as long as it's before drawing the actual line, so give it a shot!

-On rotated boxes you're doing a good attempt, just make sure you try in future attempts the trick I showed you of keeping them very very close together so you can easily draw parallel lines.

Lastly on organic perspective you're also doing a good attempt, but the main thing is that you aren't using the ghosting method on your lines. Before drawing any line you have to draw starting and ending dots, it's extremely important so don't miss it in the future!

In the exercise in general as you're are doing already some good attempts at the perspective you can try making the perspective of the boxes vary a bit, and make the ones that are closest to us more extreme and the ones that are further away smaller. Give a shot to doing some overlaps on the boxes as well, right now you're drawing all of them pretty seperated.

Overall like I said you're doing a good job. Just make sure you always draw starting and ending dots for all of your lines before drawing them, and that you try to loosen up a bit and draw your lines and ellipses more confidently.

That being said, don't forget to do warmups from now on and good luck on the box challenge! Remember to ask any question you have and keep up the good work!