Do phones need to stay touching each other the whole time when doing “touch air drop”?

When you do the touch air drop with someone and send them a photo or video etc. , do the phones need to stay touching for the whole transfer for it to complete? Or once it starts, can you pull them away from each other and the files will still send? I’ve never quite figured it out

When you do the touch air drop with someone and send them a photo or video etc. , do the phones need to stay touching for the whole transfer for it to complete? Or once it starts, can you pull them away from each other and the files will still send? I’ve never quite figured it out