When you add a dependent, the amount of the deduction reduces your tax liability. So you will not get a refund of $4,050 for that dependent, but the total amount of tax liability owed to the IRS decreases by this amount.
The refund/balance-due amount is an ever-changing number based on information that is added to the program, so the refund will increase/decrease based on income, deductions, credits, etc. as you go through the tax return.
When you reach the "Review" section of the return and all information is entered and you are ready to file, the refund amount shown at that time is a more accurate representation of the refund/balance due to the IRS.
