Unicode standardizes the character, not the artwork

The Unicode Consortium assigns each emoji a code point and an official name, but it doesn't dictate exactly how that emoji has to look — each company designs its own artwork for every emoji in the standard.

Why Apple, Google, and Samsung all look different

Apple, Google, Samsung, and other vendors each maintain their own emoji font, which is why the same 'grinning face' character can look rounder and more cartoonish on one platform and flatter or more geometric on another.

What this means for a message you send

When you send an emoji, the character itself travels, but the image is rendered locally using the recipient's device and font — so what you see when composing a message isn't necessarily what the other person sees when it arrives.

Practical implications

This is part of why a specific emoji's tone can feel slightly off across platforms, and why apps like Twemoji (used on many websites, including this one) render a consistent, platform-independent art style rather than relying on whatever font happens to be installed.