Private imgs As Image() = _
    New Image() {Image.FromFile("..."), _
                 Image.FromFile("..."), _
                 Image.FromFile("..."), _
                 Image.FromFile("..."), _
                 ... }
 
Private index As Integer = 0
 
Private Sub Click()
 
    Dim len As Integer = imgs.Length
    index = (index + 1) Mod len
 
    lbl_1.Image = imgs((index + 1) Mod len)
    lbl_2.Image = imgs((index + 2) Mod len)
    lbl_3.Image = imgs((index + 3) Mod len)
    lbl_4.Image = imgs((index + 4) Mod len)
    ...
 
End Sub