Managed - Images whose originals are stored in the Aperture/iPhoto library are called "managed images". Managed images are always accessible by Aperture and iPhoto. This means Picturelife will have no trouble identifying and uploading both your original photos and their edited versions.
If the library is managed, Picturelife will have no trouble identifying and uploading both originals and versions.
Referenced - Imported photos whose originals haven’t been placed in the library are called "referenced images". The original referenced images are often stored in an external drive to save the user computer hard drive storage space.
If the library is referenced, the storage device you use to store the original photos needs to be connected to the computer while you're uploading to Picturelife. It's worth taking the time to connect the drive, open Aperture or iPhoto locally, then make sure you can open the library from within the program - if Aperture / iPhoto can identify the originals, so can Picturelife.
Both managed and referenced libraries have pros and cons. It's important to know which type of library you're using.
It's possible to use a managed or referenced library with iPhoto and Aperture, but it's more common with Aperture. You can read more about Managed vs Referenced libraries on Apple's website, here: Aperture Managed vs Referenced - Apple Support Site