A code fragment, which appears to be part of the original PEP implementation, attempts to prevent PEP being used for XEP-0084 (User Avatar), at least for uploading an avatar.

The way that this is implemented (checking the node ID for a specific value) won’t work

It is implemented as follows in IQPepHandler:

This check should be removed, as it’s not doing anything.

There’s an argument to be made that XEP-0084 Avatar uploads do not interact with the existing VCardManager infrastructure. This is something to address, possibly with help of XEP-0398 based conversions.