The first bit of info we got about DD was a 2 minute phone call followed by a three line e-mail. It included the point that DD was to move to ours 'in a few days' on a foster-to-adopt basis.
DP and I both literally had wobbly knees when we (individually) got that phone call. Had to sit down. On the muddy ground in my case.
There was precious little info to go on, but there was definitely a 'why not' thing, so we got ready for a little one to move in shortly. Getting ready involves not only practical stuff but also getting into the right mental state. And that mental state meant that we then started thinking of DD as 'ours'.
So yes we did in a way feel an instant 'this is it' thing, but not really based on anything, not a photo, not any info. Just wobbly knees. But I suppose that was more about the prospect of having a 'generic' new little human being moving in in the very near future, rather than a feeling about this particular human being.
Things then didn't quite turn out as expected, the 'few days' morphed into 77 loooong days. In which it felt, at times, as if 'our daughter' was being kept from us.
When we first saw a photo, about half-way through those 11 weeks, it was weird. At first it was anticlimactic. I was very nervous and was expecting huge emotions to come with seeing the picture, but what I saw was just 'a photo of a baby'. Nothing special, just your average baby, unsmiling, cute as babies are but not particularly cute or beautiful, no heart-string-pulling.
But then I was shown the picture again, and I saw my daughter. And she was beautiful. Obviously.
I think that this feeling of a child being 'right', and accordingly starting to think of this child as 'yours', leaves you incredibly emotionally vulnerable. I don't necessarily think it is desirable, at the stage where nothing except this emotion links you to the child, and so much can still go wrong. I couldn't even say it provided me with much certainty that we were making the right decision. For many long weeks I was secretly terrified that something objective and rational would turn up that would mean we'd have to say no to this match. That would have devastated me - I can't put into words how terrible that would have been.
But I do know people who this did happen to.
I think that making the decisions on a cool, rational level, and then making that emotional leap of faith and allowing the emotions to grow along with the growing certainty that this will actually happen, is a far less risky way of doing things.