Could you tell us where you are seeing this?

@TiffanyL It's one of the steps in the regular online filing for 2020 taxes thru TurboTax, when it is asking questions such as "are you a dependant on someone else's taxes" and "Have you moved, started a business," etc. If that is not enough info, totally my fault! I can probably log back in and grab a screenshot of the question in particular (I'd scribble personal info of course, haha) 
Regardless, thank you so much for getting back to me! I really am kind of terrified of filing incorrectly! 

The reason the question is being asked is because, If your earned income was higher in 2019 than in 2020, you can use the 2019 amount to figure your EITC for 2020. This temporary relief is provided through the Taxpayer Certainty and Disaster Tax Relief Act of 2020.

To claim the Earned Income Tax Credit (EITC), you must have what qualifies as earned income and meet certain adjusted gross income (AGI) and credit limits for the current, previous and upcoming tax years

Earned Income and Earned Income Tax Credit (EITC) Tables | Internal Revenue Service (irs.gov)

You can go to the earned income credit section in Deductions and Credits. 

You still MUST enter all of your 2020 income into your 2020 tax return, including any unemployment you received.

Please follow these steps in TurboTax:

1. Login to your TurboTax Account 
2. Click on the Search box on the top and type "EIC"
3. Click on “Jump to EIC”
4. Answer the questions until you reach the screen "Do you want to use last year’s earned income?"
5. Note your current refund amount using your 2020 earned income at the top of the screen.
6. Click "Yes", enter your "2019 Earned Income" if the field is blank and click "continue".
7. Compare the new refund amount using your 2019 earned income with the previously noted refund amount using your 2020 earned income.

I want to use my 2019 tax return to file for 2020 ... (intuit.com)