Purpose
This paper explores how platforms shape the representation of iconic architecture across visual social media platforms, particularly how their unique features and affordances impact these representations.

Design/methodology/approach
This paper develops an integrated framework connecting iconic architecture representation, platform affordance and triadic spatial theory. Taking Rotterdam’s Markthal as a case study and collecting multimodal data from TikTok, Instagram and Google Maps, the paper uses a mixed-methods approach that integrates content analysis with qualitative coding and quantitative image/video label detection and image clustering.

Findings
TikTok is more associated with enriching lived space by enabling users to share vibrant, personal experiences and activities. Instagram influences perceived space more by shaping how users view and experience the physical environment through curated visual content. Meanwhile, Google Maps effectively shapes conceived and perceived space by users’ feedback of place ratings and reviews.

Research limitations/implications
Understanding how platform affordances influence the representation of iconic architecture helps designers and researchers generate design strategies and guides marketers in strategically selecting effective social media platforms for architecture promotion.

Originality/value
This research addresses the gap in understanding the impact of platform affordances on social media representations, especially through comparisons across multiple visual social media platforms. Its novel contribution is introducing the concept of affordance from media studies to architecture and urban studies while enhancing traditional text analysis with computational methods for analysing videos and images.

In the new media era, media architecture often serves as attractive urban spectacles and is widely represented and promoted on social media. Meanwhile, images and videos on social media also have an impact on the place identity and media architecture in the urban experience. This study argues that social media expands the conceptual scope of media architecture, aims to explain the mechanism of the impact of social media on online/ offline media architecture, and designs a methodological framework for analyzing the mechanism. Taking Grant-Tang Mall, a pedestrian street popularized by media architecture on social media, as a case study, the study analyzes the impact of social media on place branding, cultural space reproduction, and placemaking through media architecture. The findings show that social media promotes the online representation and dissemination of media architecture. Social media also combines cultural offline activities to promote citizen participation, shape collective identity, and transform offline media architecture for placemaking.