I had a similar experience not for a Director Level job but for a senior level position. I was brought out half way cross the country to meet with this company. They did not express that I would have to do any kind of skill test. I had this product category represented in my portfolio. Showed up and proceed to have a pretty normal interview then they were like ok time for a sketch test and hand me paper and some random pencils and markers. They said I would have as long as I wanted. I felt board line offend to have this surprise test and it was very board like find problems with the products and show solutions. I had only really looked at the products on line briefly before the interview and had not really put much thought in to issues the products had. Well in 45 minutes they came back and said pencils down. This was very shocking giving I was told I had a lot more time and I was no were near finished even with some basic thoughts. All and all I was happy not to get an offer form them at the end of this whole process it would have been nice to be able to prepare for the test a head of time.