The details link under Changes in dependency for any downstream job shows the changes in the current build and the last change/revision from the previous build. New users only expect to see the changes in the current build.

Example:
We have two jobs, Job A and Job B. Job B is a downstream job of Job A.

Job A builds build #1
Job B builds build #1 with changes from Job A #1

Job A builds build #2 and #3
Job B builds build #2 with changes from Job A #2 and #3

Actual behavior:
Clicking on (details) under Changes in dependency on the page for Job B's build #2 shows Job A's build #1, #2 and #3

Expected behavior:
Only Job A's build #2 and #3 should be shown in changes in dependency.