Same process has different environmental variables in /proc/pid/environ when seen from different sessions. Why?

Question

I was checking environmental variables of bash process of an xterm that was started inside vnc session.

If I check the environmental variables from the bash session itself by running env or cat /proc/pid/environ | strings, it shows all the environmental variables that would generally be set when we do su or ssh i.e., from /etc/profile and .bashrc. But when I do cat /proc/pid/environ | strings from a putty session, it shows completely different variables.

Putting aside why only those specific variables are set, I want to know why environ of same process has different results when checked from different sessions like a double slit experiment. I understand that proc is not real filesystem. But what exactly is happening when I'm querying it and so is proc not realiable way to check remote process environment?

I wrote the question from my phone. So, I don't have any sample output to show. But, I hope you get my question.

Answer 1

Here is what I did for a test:

$export test=one
$vim test1

pid = 1200, Stopped the process with CTRL-Z

$cat /proc/1200/environ | strings
test=one

Now for second process

$test=two
$vim test2

pid = 1201, Stopped the process with CTRL-Z

$cat /proc/1201/environ | strings
test=two

The user might have changed the environment properties before running the program.