That's actually the new-ish Live View Editor.
Design View doesn't have the blue outlines and tabs (called Live View Displays). You can switch from Live View to the old Design View in the Document Toolbar, found under Window > Toolbars > Document (make sure it is checked).
If you want to continue using Live View, without the displays, you can turn them off when Live View is active, under View > Live View Options > Hide Live View Displays.
Thank you Jon_Fritz_II,
View > split > code-design turned these off for present and future web pages.