'What is the meaning and effect of this technique?' should be correct.
One of the main tools of a successful text interpretation is to understand which writing features an author is using and its respective effects. Since the literary techniques (a.k.a. 'language techniques') are often used by authors to give their written ideas more emphasis and make them stand out, besides conveying and heightening meaning to them, the more you know about these devices, the better reader you are.