Sure. Let’s say you have a commit C that makes changes to file A and file B.
Regular git log -p -- A will show all commits that touch file A, and for those commits, it’ll show the diffs to A.
With --full-diff, it’ll show the same commits, but for each commit it’ll show the diff of all files changed in that commit. In this case, commit C’s diff will show diffs for files A and B.