Difficult to accurately judge from the photo, but appears to be a relatively long time between touch-down and actuation of full reverse thrust. Readers know that reverse thrust is most effective at high speed. This means a fast manual selection of the reverse levers to full reverse immediately on touchdown. On slippery runways, and if wheel spin-up is slow, automatic speed brakes may not operate and it is necessary to raise the speed brake lever manually immediately on touch-down if max stopping capability is to be realised.
In the simulator it is often observed that some pilots lift the reverse levers up slowly as if to graduate the amount of reverse. It is a faulty technique and often results in delayed spool up in reverse. Obviously this is undesirable on a slippery runway where wheel braking efficiency can initially be very low, despite auto-brakes operating. Full and immediate reverse may be the only effective retarding force after touchdown and until the brakes begin to bite. This is where good quality simulator training on wet runways is vital.
The video should be used as an excellent training tool as it is a very rare display leading to an actual accident. The following link depicting several stills where the aircraft finally stopped, is borrowed from another thread on the same subject called How to lose two A310 before Christmas.
http://avherald.com/h?article=49150489&opt=0