Transaction Insight is a feature of MetaMask that appears during the transaction flow, or in your transaction history. It looks like this:
The point of Transaction Insight is to make the information regarding your transactions readily understandable. Under the hood, it decodes the transaction data, which normally comes through as a blob of code:
This is fine for computers, but it’s not very helpful for most humans. With Transaction Insight, by clicking on the ‘DATA’ tab, you're offered a decoding of that blob into a number of fields. Right away, you’re presented with a much better understanding of your transaction’s details.
Keep in mind that some of the numbers are measured to a very high degree of precision, meaning the decimal point may not be in the same place as you’re expecting. This is something we’re working to clarify as soon as possible.
What’s more, you now have a set of tools to help you ensure you’re interacting with the right contract.
For example, addresses involved in the transaction will be presented in their standard format, but you can also click on them to nickname them, so that in the future you know you’re interacting with the one you mean to. That way, you're much less likely to interact with a scam address instead of the legitimate one.
Additionally, armed with the knowledge of specific contract addresses, you can do your own research on Etherscan to make sure you understand exactly what’s happening with the contents of your wallet.