While recreating this problem (for the 4th time, but after having 8 hours of sleep), I found where I went wrong.
On the Backup Image Dependencies screen, I think I failed to select all of the incrementals as well as the base job. I must have just assumed it would roll up all of the incrementals for me. It didn't occur that I would be given the option to select which incrementals to roll into the image.
This time around, I selected them all, and when I mounted my VM, all of the e-mails were there.
Is there a way to get the logs from a previous run of the Backup Image Tool? I only see the log from the current one, and the backup history tab only seems to have logs from the regular backup job. I'd like to compare what i did this time with what I did last night.