Because of new upgrades where you can, quote, "see your package early", the problem that they are using sale tactics for certain shipping to be able to see your package early. But really, they x-ray it beforehand, just like they do in customs. So unless the vendor you are using has veteran/legendary/efficient/international shipping leveled stealth to use first class shipping, I wouldn't risk it. I have a feeling that a lot of hate is about to flow into this post, but I'm just letting you guys know. That's why I said you can take it with a grain of salt, if you want to.
No, they don't. They're literally just taking a photo of it while it's moving through the automated sorting machine, the same as they have been ever since 2002. The only difference now is they've hooked up that system to the internet so you can see that picture too.