A novice trying to understand .Tag

Sub Globals
   Dim scr_Buttons As HorizontalScrollView
   Dim icon1, icon2, icon3, icon4, icon5 As Bitmap
   Dim viewImage As ImageView
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("Busca_Categ") ' There is a HorizontalScrollView named "scr_Buttons" here

   icon1.Initialize(File.DirAssets,"icon_01.png")
   icon2.Initialize(File.DirAssets,"icon_02.png")
   icon3.Initialize(File.DirAssets,"icon_03.png")
   icon4.Initialize(File.DirAssets,"icon_04.png")
   icon5.Initialize(File.DirAssets,"icon_05.png")
   
   Dim xPos As Double
   
   For T = 1 To 5
      viewImage.Initialize("Imagen")
      xPos = (T-1) * 65dip
      Select T
         Case 1
            viewImage.Bitmap = icon1
            viewImage.Tag = 3
         Case 2
            viewImage.Bitmap = icon2
            viewImage.Tag = 5
         Case 3
            viewImage.Bitmap = icon3
            viewImage.Tag = 15
         Case 4
            viewImage.Bitmap = icon4
            viewImage.Tag = 8
         Case 5
            viewImage.Bitmap = icon5
            viewImage.Tag = 13
      End Select
      scr_Buttons.Panel.AddView(viewImage,xPos,0dip,60dip,60dip)
   Next
End Sub

Sub Imagen_Click
   Dim Send As View
   Send = Sender
   Msgbox("Selected Image: " & Send.Tag,"Message")
End Sub