The example is meant to demonstrate that whether I say 平 as ping or peng changes the meaning of the sentence. It does not depend on how I feel like it.
Another example: I buy some raisins, and the lady gives me some. I say: 咁多! If I pronounce "gam3do1", I say "That's so much!". If I pronounce "gam3doe1", I say "That's so little!".
(Yes, contrived. Almost always the former is used. But both can be.)
Another example: I buy some raisins, and the lady gives me some. I say: 咁多! If I pronounce "gam3do1", I say "That's so much!". If I pronounce "gam3doe1", I say "That's so little!".
(Yes, contrived. Almost always the former is used. But both can be.)