Check a macro that rotates the current (selected) picture by 45°:
Sub Macro1()
Const angle = 45
Dim s As Shape
For Each s In Selection.ShapeRange
s.IncrementRotation angle
Next
Dim inl As InlineShape
For Each inl In Selection.InlineShapes
Set s = inl.ConvertToShape
s.IncrementRotation angle
s.ConvertToInlineShape
Next
End Sub
You can also assign a value to s.Rotation.
Backup your document before tests.