This study explores the visual style differences in Instagram posts by multinational brands across different cultural markets from a cultural perspective. With its visual-oriented features and diverse functionalities, Instagram has become a crucial platform for interaction and communication between brands and consumers. Therefore, how brands design their Instagram posts to attract consumers is of great importance. Previous studies have shown significant differences in cultural tendencies toward uncertainty avoidance (UA). This study aims to investigate the relationship between the visual styles of Instagram posts and levels of uncertainty avoidance and further understand how cultural factors influence consumer perceptions and behaviors. Study 1 analyzed Instagram posts from multiple multinational brands by examining the proportion of visual elements in the images to identify design trends across different cultural contexts. Study 2 used Instagram posts from a fictional brand as experimental stimuli and collected participants’ responses through a questionnaire to examine their perceptions of and behaviors toward the brand. The results indicate that posts with more detailed information effectively reduce consumers’ uncertainty and significantly enhance brand trust and liking among high-UAI participants. This study provides cross-cultural insights into Instagram visual marketing strategies, particularly for high uncertainty avoidance cultural contexts. Additionally, it highlights the cultural differences in Instagram visual marketing, offering new perspectives and empirical evidence for future research.