The site's navigation changed in early October, 2016.

 

For Hilo Daily Image pages with the larger image and "previous image," "this month," and "next image" at the bottom, you can click on the left third of the image, the center, or the right third to move around.

 

For the more recent images, you'll see the "previous" and the others at the right. This means you can click in the top third of the image for previous, center third for the month, and bottom third for next.

 

Eventually all pages will have the same navigation tools, but that's going to take time.