I can't see your visio right now but I assume it is something like this
pix1 -> vpn tunnel -> pix2 -> inside -> syslog server
and you want to syslog from pix1 to the syslog server?
This is possible and you must...
1. Add the outside interface address to the interesting traffic crypto acl's on both pixes.
pix1
outside interface = 1.1.1.1
syslog server = 192.168.1.1
access-list crypto permit ip host 1.1.1.1 host 192.168.1.1
pix2
access-list crypto permit ip host 192.168.1.1 host 1.1.1.1
2. Add the logging statement to pix1
logging host outside 192.168.1.1
Hope this helps, please rate helpful posts.