I will try to cover a number of techniques for enlarging the photos so they are easier to view.
1. I am working from a Windows 8.1 desktop computer - I assume that what I am about to say will also apply to other Windows versions and also to Windows laptops. Please let me know if I am wrong. In this environment, click on any photo in a set using your mouse (or with your finger if you're using a touch screen). An album of photos from this post will come up. You can scroll through the images one-by-one by simply clicking on the main image on the screen or advance faster by clicking on any of the preview images along the bottom of the screen. You can exit this album at any time by clicking on the x in the upper right corner. To view the photo still larger - much larger - right mouse click on the photo and select "View image" from the drop down menu. Your mouse pointer will now turn into a magnifying glass. Left click on the image to view full size - use the scroll wheel on your mouse to scroll up and down through the image. When you are done, press the backspace key or the back arrow in your browser to return to the Yearbook.
2. In Windows 10, right click on an image, select the option to open the image in a new tab. Go to the new tab, then the mouse cursor will become a magnifying glass - click on the image and it will expand.