For the printed application they require the witness to sign the witness page, as well as write their name and signature on the back of a printed photo of you. How does this work if you apply online? Do I still need to have a printed photo and obtain a physical signature from the witness? If I do need to print a photo, does it have to be printed on special photo paper (i.e. what they demand for the main photo during a printed application)?

If it makes any difference, I'm applying for my first ever passport and I don't have a verified RealMe.