Its the DVSA nowadays and has been for sometime, and they do ‘speak’ to the DVLA.
When the workday is finished all the tests for that day are posted via the Royal Mail to the Newcastle office, where they join a big pile of test results from all over the UK, eventually your test will be scanned onto the DVSA computer system that is linked to the DVLA and at that point the DVLA will be informed of the need to issue a licence. This process can take a few days and can be affected by several factors, such as; if the post box used will have a late pick up, the backlog at DVSA etc
Your DL25 (test report) will have a mark on the no box which informs DVLA that you will be applying via post yourself as you weren’t eligible for automatic driving licence issue, in your case because the photo needed updating. So now someone in Swansea has to marry up the electronic report with your postal application.
Easy peasy and it’ll be online for you to view by the middle of next week.