Leave max depth at 1 and
change the exit color to red.
Assign this material also to the
small teapot.
Render again.
Now all reflections of reflec-
tions turn red instead of black.
The max depth is a way to low-
er render times in scenes with
lots of reflective objects. But
by lowering the reflections, the
exit color will likely come into
play. Sometimes it is therefore
useful to change this to another
color than black, something
more appropriate for the scene
for example.