Question

Look at this cell phone. It's like a chameleon.
- What do you mean by that?
-It changes its color accoring to the temperature.
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Can we use "What's that supposed to mean?" instead of 'What do you mean by that?" Are both the same? When do we use "What's that supposed to mean?"

Answer 1

yes

Answer 2

Both sentences mean the same thing, yes. You can use either phrasing whenever you choose.