Sometimes, while looking through domains/URLs on Site Explorer, you might come across pages that have a higher UR, but lower DR (like the above example).

Why? 

Let's take a look at the definition of both UR and DR. 

URL Rating (UR) is a metric that shows how strong a target URL's backlink profile is on a scale from 1 to 100. Generally speaking, each referring page passes its rating score to all the pages that it links to.  

Domain Rating (DR) is a metric that shows the strength of a given website (domain)’s overall backlink profile. Generally speaking, each referring domain splits its rating equally amongst the domains it links to. 

Within the definitions lies the answer. 

While they are both backlinks-based metrics, UR compares pages to pages, whereas DR compares domains to domains. They are not measured on the "same scale". 

Therefore, a page with many high-UR links (therefore creating a high UR page) can exist within a low-DR domain.