It appears that the new arrangement is an attempt to compete with the scheme run by Amazon, that allows customers to order items online and collect them from a growing number of secure passcode-protected lockers based in local retailers.
The move to a hybrid service, combining online ordering and local collection points, is gaining ground in the retail environment as customers and retailers seek a solution to the home delivery issue.
Argos do already run a call & collect service which has proved popular, this extension to the service appears to be a perfect fit. It will, however be interesting to watch the development of the service as there is bound to be some crossover of products between the two retailers who will be competing on price. This may be the main reason that this arrangement is initially a six month trial.