The current user experience of checking a large modification of a task description is quite terrible. There are the "Old" and "New" tabs which contain the entire old/new text without any indication of what changed; and the "Diff" tab which uses an inline diff with a not particularly smart diff algorithm, resulting in hard-to-read change soup like this:

Reviewing task description changes is not something that's needed often, but when it's needed and the description is long and the change is big, it can be quite painful. Phorge should support side-by-side diffs like all decent diff tools.