IRCC will transfer filed to different offices based on multiple factors, such as workload distribution and processing requirements. Immigration law and the regulations specifically state where an application must be submitted, but they do not stipulate where an application must be processed, which can be at any visa office in Canada or abroad.
During the course of processes, even if your submitted electronic application, there may be a paper application generated based on documents that come in form other agencies, provincial immigration offices (if PNP) etc. and thus the paper file may also have to be transferred along with the electronic file for father processing.
The protocol for application tarsier is available at:
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/service-delivery/file-transfer.html