I, too, am not 100% sure what you mean. I think I know, though.
Try like this:
  
Private ArrayOfPics(1 To 3) As Picture  
  
Private Sub Form_Load()  
    Set ArrayOfPics(1) = LoadPicture(file1)  
    Set ArrayOfPics(2) = LoadPicture(file2)  
    Set ArrayOfPics(3) = LoadPicture(file3)  
End Sub  
  
Private Sub Timer1_Timer()  
    Static i As Long  
  
    If i = UBound(ArrayOfPics) Then  
        i = 1  
    Else  
        i = i + 1  
    End If  
  
    Image1.Picture = ArrayOfPics(i)  
End Sub