With the e-filed return, neither one was submitted as IRS does not need it. It is a tax computation worksheet and IRS knows it was used, and they recompute the tax anyway, it is not necessary to be part of the return.
You can go to print your return and save it a pdf with all worksheets and then see this tax computation worksheet.
It is not part of your return, as it is the worksheet for the tax computation only, so IRS does not require it.
Whenever there are capital gains and/or qualifying dividends, the tax is computed this way.
For several years, the IRS has provided a tax computation worksheet in the Form 1040 and 1040A instructions for certain investors to get the benefit of the lower capital gains rates without the need to complete Schedule D.
The worksheet is for taxpayers with dividend income only or those whose only capital gains are capital gain distributions reported in box 2a or 2b of Form 1099-DIV that were received from mutual funds, other regulated investment companies, or real estate investment trusts. Taxpayers must still use Schedule D if any amount is reported in box 2c, 2d, 2e, or 2f of Form 1099-DIV or in certain cases when Form 4952 is being filed.