How does Netfilter handle BROUTE chain Link Layer data in Network Layer?

[SDF07S]

There is a way to use Netfilter EBTables BROUTE chain to force Link Layer data to go directly to Network Layer for filtering, but Link Layer can filter frames that Network Layer cannot. If I use BROUTE for LLDP frames, then what does Network Layer do with such frames? IPTables only works with Layer 3 packets and ARP. What can it possibly do with LLDP frames or any other Layer 2 information it receives? Here's the diagram:

 

[sfx2000]

Recall that LLDP is typically over the LAN only, and not forwarded...

It's a security risk to do so otherwise.