Here is sample code using Image (Image and TextFrame share the same base class):
Code:
// Create image, 2 cm from top-left corner:
var image = document.LastSection.AddImage(@"C:\Users\...");
image.WrapFormat.Style=WrapStyle.Through;
image.WrapFormat.DistanceTop = "2cm";
image.WrapFormat.DistanceLeft = "2cm";
image.RelativeVertical = RelativeVertical.Page;
image.RelativeHorizontal = RelativeHorizontal.Page;
// Create image, 2 cm from top-right corner:
image = document.LastSection.AddImage(@"C:\Users\...");
image.WrapFormat.Style = WrapStyle.Through;
image.WrapFormat.DistanceTop = "2cm";
image.WrapFormat.DistanceRight = "2cm";
image.Left = ShapePosition.Right;
image.RelativeVertical = RelativeVertical.Page;
image.RelativeHorizontal = RelativeHorizontal.Page;
// Create image, 2 cm from bottom-right corner:
image = document.LastSection.AddImage(@"C:\Users\...");
image.WrapFormat.Style = WrapStyle.Through;
image.WrapFormat.DistanceBottom = "2cm";
image.WrapFormat.DistanceRight = "2cm";
image.Left = ShapePosition.Right;
image.Top = ShapePosition.Bottom;
image.RelativeVertical = RelativeVertical.Page;
image.RelativeHorizontal = RelativeHorizontal.Page;
"2cm" is the distance from the edge of the page. "image.Left = ShapePosition.Right" is a bit cryptical, but it works.