Was this use of  tags in this HTML over background images better?
The use of ul seems appropriate. My concern with using &lt;img&gt;s would be with the image dimensions. From what I can see above, unless you create your images specifically in those dimensions, it will become a pain to ensure they scale correctly.

I've found that if you want to preserve a predetermined width and height for your images without ruining the aspect ratio it's almost always easier to use background-image rather than &lt;img&gt; tags. 

Using background-size: cover you can ensure that the image covers the available space, without losing the ratio:


  The cover value specifies that the background image should be sized so
  that it is as small as possible while ensuring that both dimensions
  are greater than or equal to the corresponding size of the container