Formatting information is stored in the sheet; it’s separate from your data. Formatting information isn’t included when you export your data to a backup.
When you import data from a backup into a new sheet, you may need to reapply formatting (word wrap, bold, conditional formatting) once you’ve reimported your data.
If your sheet includes hierarchy (indenting or outdenting to create subtasks), the rows will be grouped in outline format in the exported Excel file. Click the + (plus icon) to the left of the row numbers in Excel to expand any collapsed rows to reveal their subtasks.
For more information about using hierarchy in Smartsheet, see Hierarchy: Indenting & Outdenting Rows.