For in person application always carry your laptop and be prepared to use ur data to correct your application.If you got the photos clicked at BLS, then it means you would have had to scan and upload them to the OCI application, there and then, correct?
Things to consider for this I guess are Wifi/Data at the premises.
Also, in general, can the online applications (SC and OCI) be updated/edited any number of times?
One can try to submit application any number of time, no possibility of correction - start from beginning.