Glad it's working. The problem with your code is that the picture will not be a msoEmbeddedOLEObject
It may be an MsoLinkedPicture or maybe msoPlaceholder with ContainedType = msoLinkedPicture
Code:
Sub pixUpdater()
Dim osld As Slide
Dim oshp As Shape
For Each osld In ActivePresentation.Slides
For Each oshp In osld.Shapes
If oshp.Type = msoLinkedPicture Then oshp.LinkFormat.Update
If oshp.Type = msoPlaceholder Then
If oshp.PlaceholderFormat.ContainedType = msoLinkedPicture Then oshp.LinkFormat.Update
End If
Next oshp
Next osld
End Sub