Xayaburi Dam under construction, July 2015. (Taken from this PP presentation by Pöyry, posted on a Laos government site.)
In an Interpreter post on 14 December 2015 ('What's Happening on the Lower Reaches of the Mekong River?'), I referred to a YouTube video that gave a rare, relatively up-to-date view of the controversial Xayaburi dam being built on the Mekong by the Lao government. Shortly after the post was published, the video was taken down.
Now, in response to enquiries from a Cambodian NGO, I have made a further search to see what, if any, images are available that provide some sense of just how substantial the Xayaburi dam actually is and what construction has been achieved so far. This search has located a Powerpoint presentation by Poyry, the Finnish engineering firm working on the dam, which provides considerable detail for what had been achieved by July 2015 as well as providing a large amount of engineering detail.
As has been pointed out by various commentators in the past, there appears to be a clear conflict of interest in the fact that Poyry has played two roles in relation to the Xayaburi dam, both as the dam's supervising engineer and in providing a positive assessment of its compliance with calls to rework the dam's structure in the light of criticism from Cambodia, Vietnam and a range of NGOs. Some comment on this issue is usefully summarised on Wikipedia.
Any sense that the Xayaburi dam is a minor construction on the Mekong is eliminated in the Poyry Powerpoint presentation. Substantial in size and with untested measures designed to facilitate fish passing through the dam and to minimise the retention of sediment, there seems every reason for the concerns raised by critics to be taken seriously.