Why am I getting $407 in state return when on my W2 it says $457

Just because the W-2 says your employer withheld $457 does not mean you get it all back.  The state is keeping some.

You must owe $50 tax on your income.  The withholding on your W2 is just an estimate of your tax at the end of the year.  

Why do I owe the state $50??

Because you have to pay tax on your income.  If you didn’t they wouldn’t take any withholding out.

How lucky you are to only owe $50 of tax to the state. 

Your job withhold tax based on the W-4 or other forms that you give them and based on tax tables provided by the state and the IRS. The goal is to have you pay slightly more into the system then you owe so that you get a modest refund.

In this case, you seem to owe $50 of state tax.   Because you had $457 withheld, this results in a $407 refund.