© The Author(s) 2019. This study explores the image sharing site Instagram to reveal how affordances, or uses of the platform, occur within a nexus of technological architecture, sociocultural contexts, and globalized commercial practices. It suggests social actors draw upon Instagram’s affordances at material, conceptual, and imaginary levels while using social media. This triadic model for theorizing affordances of Instagram responds to the need for mapping ontologies and typologies of social media within increasingly visual, intercultural, and non-Western contexts. The lenses of critical multimodality and a participant-centered method consider how female Gulf-Arab social media influencers operate through an interplay of shifting affordances in ways that challenge current conceptions of authenticity surrounding social media influencers. It is suggested that the triadic affordances of Instagram, occurring at material, conceptual, and imaginary levels, provide both influencers and followers with strategies of “fantastical authenticity” for navigating conflicting modes of representation and self-presentation within local and globalized economies.