Where is sudo hiding my root's .Xauthority data?

I just noticed something peculiar about how sudo handles the .Xauthority file:

-bash
sudo xauth add $(xauth list | tail -1)

user@server: sudo xauth info
Authority file:       /root/.xauthYZ21Nt
File new:             no
File locked:          no
Number of entries:    1
Changes honored:      yes
Changes made:         no
Current input:        (argv):1

user@server:  sudo xauth info
Authority file:       /root/.xauth3BFy5d
File new:             no
File locked:          no
Number of entries:    1
Changes honored:      yes
Changes made:         no
Current input:        (argv):1

user@server:  sudo xauth list
server/unix:10  MIT-MAGIC-COOKIE-1  c922ab48defdf43b1092dffb86c06eed

user@server: sudo ls -la /root | grep auth
-rw-r--r--  1 root root    0 Nov  9 14:40 .Xauthority
-rw-------  1 root root   57 Nov  9 15:23 .xauthsrxzxl

user@server:  pkexec xauth info
Authority file:       /root/.Xauthority
File new:             no
File locked:          no
Number of entries:    0
Changes honored:      yes
Changes made:         no
Current input:        (argv):1

So, $XAUTHORITY value is different in every new sudo, and it points to a temporary file which disappears when sudo quits. Because of this, the last command (which uses pkexec instead of sudo and expects it to be in /root/.Xauthority) fails to see the cookie. For instance, sudo gedit runs fine, but pkexec env DISPLAY=$DISPLAY gedit fails. Why is it done in such a complicated way, where is the data stored, and more importantly, how can I access .Xauthority data with pkexec?