1) Load both attached memory captures into Unity (I am using Memory Profiler 0.4.2-preview.1)
2) Open Memory Profiler
3) Load the earlier capture (ending in "518") as capture A
4) Load the later capture (ending in "162") as capture B
5) Go to the compare snapshots Fragmentation view
6) Make sure the Row Size is set to 8 MB
7) scroll to the managed memory just past the address "0x0000011EF800000"

Observed result
There is a 12.5MB large yellow "Modified" chunk of memory for the object CompatOctree[1638400]

Expected result
This 12.5MB is red. This allocation exists in capture A but is empty in capture B as it was garbage collected.

Also note that swapping the snapshots so that A is B and B is A is not immediately reflected in the Fragmentation view but only when going to a different view and coming back to it, only then all the red area's are green and vise versa.
Expected result: swapping the snapshots positions should be reflected immediately.