When you first use DVIview, you should set the options in the Printer characteristics group and then click on Save to permanently store this choice.
Choose Printer prints face up if paper leaves your printer with its printed side facing up.
Choose Straight paper path if paper travels through your printer along a straight(ish) route. It should enter the printer on one side and leave on the other. Many printers have a U-shaped path where the paper leaves the printer on the same side that it enters; often the out-tray is immediately above the in-tray. Don't choose the Straight paper path option if your printer has a U-shaped path.
These choices allow DVIview to print sheets in a sensible order (something that, otherwise, can be difficult to get right with double-sided printing).