I have already posted on another thread my guess.
But to make it short here:
The FBI is looking at everything, computers, thumb drives, DVD’s, etc., for child porn.
My suspicion is that Huma when she left, forgot to take something bordering on espionage. Maybe in the computer she shared or a DVD.
And that information also in some way links Hillary to it.
As you infer, there is no way the FBI is going to open the matter again just because they found another email similar to what they have already.
If this was only about Huma, the FBI would’ve opened a NEW investigation on Huma...There is definitely something here involving Clinton or the original investigation would’ve stood...
1. Anthony Weiner gets caught (once again) sending "sext" messages to a minor.
2. Huma announces that she's leaving him. She probably has no intention of leaving him (I say this because they're supposedly still sharing an address in New York), but this incident is particularly embarrassing because some of his lewd photos have their young child on the couch next to him.
3. The presence of the child in a lewd photo makes this a matter for NYC's child protective services agency and/or the NYPD.
4. As part of their investigation, the NYPD gets a warrant for Weiner's iPhone and/or his phone records. During the course of their investigation they find a whole boatload of e-mails, texts and other communications that have nothing to do with their investigation but contain compelling evidence that they involve a Federal matter outside the NYPD's jurisdiction.
5. They turn their entire pile of evidence over to the FBI.