1) Artwork unfinished : It's a good thing I take pictures of every art piece my students complete for my own review. I was browsing through the photos and spotted the mistake. I have seen this art work numerous times, yet I did not realize it was incomplete. Luckily this is an easy fix. I just need to call the students home and ask the parent to send it back (yes it is that important to me). The student only needs to touch-up/fill-in an area (blue area to the right). This may not seem like that big of a deal, but I don't feel it will represent the 4th of July until this is done. It shouldn't take no more than 5 minuets.
2) Art Lesson Improvement. I would not go as far to say that this lesson was a complete failure because I received some pretty good results. But after the lesson was completed, it became clear how it can be improved. This is the problem with brand new lesson plans. The mistakes are not foreseeable. Ways to improve are (a) create the lesson before it is implemented, if possible, and (b) seek advise from a more experienced teacher.
The moral of this post is, teachers will make mistakes. Don't freak out if you realize you did something wrong, just make sure you do everything you can to fix it and avoid doing it in the future. Please don't be afraid to ask someone for help. It is good to collaborate with someone. Teach and LEARN :)