Despite its odd window size and interface, Blink for Mac works well and offers an interesting way to see small changes in two images. The program opens quickly and also downloads with a set of example images, which demonstrate its functionality well.
After starting, the program's initial window seems far too large. It is impossible to see the actual operating buttons along the bottom, and an option to change it to the full screen could not be located. After playing around for a while to figure out the window problem, hiding the Mac dock solved the issue, exposing the controls. After consulting Blink for Mac's download page for instructions, the app proved easy to use. After selecting photos to compare, the user must label them Picture 1 and Picture 2 and place them on the desktop. Clicking on the "Start" button automatically loads the images into the main window. The two photos switch several times a second, revealing the subtle differences in an interesting way. The rapid changes almost move like an animation. The users can also shift the image around the window by clicking up and down buttons, but the changes are so small the option has little usefulness.
For those looking for a quick and easy way to compare images, or for those who are fans of image puzzles but can't catch all the differences, Blink for Mac offers a good solution. The application is light, free, and works as advertised.