This is unusual, but possible. Code can examine the call-stack depth to determine whether it was called inside a function or script, or from the command line.
It would be more common to have code that produces different results depending on whether it called in an output context or not. For example,
fprintf('hello')
ans
0 + fprintf('hello')
ans
What is happening here is that fprintf() is examining nargout() and only generating return values in the case that nargout == 1.
Or consider the difference between
plot(1:5)
ans
plot noticed that no output was requested and so did not emit any output
h = plot(1:5)
plot() noticed that output was requested and returned the line() handles.
So code can pay attention to whether output is requested or not.
Anyhow... I would suggest experimenting with using evalc() and see what you get in the output variable.
