This red area is a section. The background color property has been set to this color. Sections can apparently use different template-based formatting to change their appearance. Inside the section, this is where the first textbox landed.
This is the second textbox. Wow these sections sure burn a lot of graphic real estate.  Note, the "body" of the page (where containers like textboxes normally live) is below. The "section" container appears to be independant of that.

​Gateway’s programming is made possible in part by support from the Georgia Council for the Arts, the National Endowment for the Arts, the Fulton County Commissioners under the guidance of the Department of Community Development, the Fulton County Commissioners under the guidance of Fulton County Arts and Culture, the City of Atlanta - Mayor’s Office of Cultural Affairs and individual contributors.