It had you use `git add '* .txt'` because there were untracked txt files in the octofamily directory. `git add * .txt` would have just added the txt files in the root of the directory and ignored the octofamily directory.

I wouldn't think this is so much an error as they _want_ you to use '*.txt' to add the files in the subdirectory along with the files in the root. They could have touched better on the difference between quotes and no quotes though.