Rational style :

• cheap (economic appeal), reliable, convenient, saving electricity
• photographic evidence (facsimile of official certificate or testimonial) : 證明 (zhengming)
• trademark (be aware of imitations, be sure to authenticate the original trademark)
• description of the quality of the product : solid, beautiful, variety of designs and colors
• propaganda for the (spacious) factory itself
• direct reference to a famous proverb or catchphrase (口頭禪 koutouchan) : beaucoup n'ont pas de preuves d'authenticité
• honesty, pratical, realistic, truth
• available to even far living consumer