Sending a message from an iPhone to an Android will result in a green bubble. This is just a text message bubble. You won’t get the fancy things that iMessage had, so you just have to know that it has been delivered and the other person has either received it and read
iPhones have this thing called iMessage which is the preferred way to message friends, family or others. When both phones have iMessage activated you will see that there is a blue bubble. Underneath the messages, you will see that it is delivered, and if the other person has “Send Read Recipients” on, it will show the other person they have read the message.
The problems come with the fact that a letter “A” is pretty easy to interpret whereas “Grinning Face With Smiling Eyes” which is the definition of 1F601 is open to some interpretation – and each platform has their own set of drawings that show their interpretation.
What you’re seeing is a drawing that represents a character code. The phone sends the character code (eg 1F601) and the receiving phone displays the symbol it has for that character code. Just the same as when you send a letter A – it’s not the drawing that’s sent, it’s the character code 065 and that means “A”.
It gets even worse though because these interpretations aren’t fixed. I believe Apple revised their emojis a couple of versions back and the Android emojis are being revised in the next major release. Prior to iOS 5, Apple’s interpretation of 1F601 looked just as scary as Google’s does.
This code in particular has been interpreted in WIDELY different ways. Sometimes it’s useful to check somewhere like Emojipedia before you send an emoji – see Grinning Face With Smiling Eyes Emoji for example and wonder what the hell the folks at Google were thinking.