This chapter studies the interface, the physical and digital touchpoints shaping how consumers perceive and interact with retail environments. IKEA provides the guiding case, showing how layout, signage, sensory cues, and product presentation make an impact on attention and influence decision-making. The chapter reviews layout models, visual merchandising techniques, pricing signals, and the role of staff in complementing automated systems with expertise and reassurance. Interface design balances functional aims – efficiency, clarity, and navigation – with experiential goals such as immersion and storytelling. Decision-support tools like simulations and planogram optimization can improve consumer and retailer outcomes. Ultimately, the interface translates strategy into lived experience, determining how consumers sense, understand, and act within the retail space.