Bill Tindall
This question required some reflection but I think I have come up with the answer-errors and omissions.

Typically there is much print wasted describing the project and insufficient details on how to put it together and what parts of the construction project involve peril. When I design something as part of the design I am unconsciously working out the details of the construction, the corresponding problems of construction that need to be solve, and the critical areas of fit. These details are often lacking in a magazine article plan and description of the construction.

Take the table in question. There was an error in the article that didn't get fixed until 2 months later. Fortunately, that didn't create any problems for me. What did create problems was not appreciating how it all folded together and what had to slide by what when it was all done. The description of construction steps didn't include details of critical importance, which I would have figured out had I done my own drawings. I don't get the big picture of construction nor the theory of construction for the these magazine articles.

I don't work well from cookbooks either. The first thing I do with a recipe that I intend to use in the future is rewrite it. My pet peeve are directions like "mix the flour and baking powder". How much!?! I have to go find that information somewhere else in the text. My recipes read "mix 500 grams of flour with 5 grams of baking powder". And rarely are there details of where things can go wrong to be watched for. You get to discover these the first time and correct the next. My cookbooks are lavishly annotated with useful notes about the pages that I have added to make a repeat more reliable.