WhatsApp uses Apple emoji images for emoji support on all platforms, including Android. This differs from most apps which use the native emojis available for each platform.
One emoji appears differently in WhatsApp to other platforms. The red heart emoji (offically known as heavy black heart) has a beating animation, and appears larger than the other emojis when sent in a WhatsApp message:
The latest version of WhatsApp for Android includes all emojis available on iPhone since iOS 9.1. In 2015, the middle finger emoji used its own custom artwork on Android devices, which has since been replaced with the same emoji from Apple's artwork.
Emojis from WhatsApp Android are displayed below.