Mirroring is the beginning
As a native Arabic speaker, I notice quickly when an interface has been translated but not reconsidered. The text may be Arabic and the layout may flow right to left, yet the experience still carries assumptions from another language and market.
RTL support reaches into navigation, icons, animation direction, charts, mixed-language strings, numbers, forms, truncation, and the tools teams use to build and test. A mirrored screenshot can look correct while the product remains difficult to use.
Language reveals the system
Localization exposes whether a design system describes intent or merely stores components. Does an arrow mean next, forward, submit, or move east? Should a timeline reverse? Which identifiers remain left to right inside Arabic text? Those questions cannot be answered reliably by flipping coordinates at the end.
The same test applies to the organization. When research, content, engineering, and quality practices only work in the source market, internationalization remains a recurring exception instead of becoming a product capability.
Design with the market, not for it
Include local language and cultural context early enough to influence the product. Research should test both the underlying proposition and the translated interface. Local teams and customers should participate in decisions throughout the work.
RTL makes hidden defaults visible. Teams build stronger global products when they test those defaults with local customers before the assumptions harden into the product system.