Faster image portfolio creation and login will help to make such a system usable. One improvement would be to reduce image size to minimize the need for scrolling, which occupied a significant portion of the task completion time.
Users wished to have more feedback in many instances, but it will be important to give users feedback without compromising security. For example, during portfolio creation and authentication, some users were confused about how many images they had picked thus far if a portfolio window was not available. If portfolios are created in a secure environment, it would be possible to show thumbnails of the selected images. In the case of an insecure environment, simply providing the number of images picked thus far would be an improvement.