Hi Philip. Caveat: Please take what you like from this and leave the rest. It's just my opinion. I'm not a professional. Nor am I an expert in flash photography. /caveat.
The most stand-out issue for me what feels like an awkwardness to your subjects. In 2, 3, 4 & 5 I get the feeling people are "leaning" into the frame. It's like they're being scrunched up. Coupled with a few smiles that don't reach the eyes this gives me the impression of tension & discomfort. #1 is much better in this regard as the older lady's smile seems more genuine and she's leaning towards the edge (rather than away from it) A little more space would be nice, but #1 is the best image for me. #4 is the best of the back-to-back poses as it seems much more natural. The smiles still seem forced though. For me - portrait photography is quite a bit about psychology and getting your subject relaxed. I tend to have a few 'lines' held in reserve to get laughs/chuckles - it's a bit like a magicians patter. I tend to explain squinching to people (which usually gets a smile just saying the word) and it gives me something to talk about to try and break the initial tension. It also gets people pulling stupid faces and relaxing into genuine smiles (which is when I pounce).
Composition is tight in all the images. The leaning in doesn't help and gives an overall feeling of claustrophobia to the set. If this is down to space, consider another location - outside even? The backdrop of white paper is showing its creases in the last image which is not a huge thing, but probably needs tidying up. I like the angle to the bodies. No-one's square on, which is nice and flattering. The older lady's specs are slightly dark (are they those reactive things?) which darkens the eyes and isn't a great look IMO. In some cases, the rims are cutting through eyes which also is something I'd try and avoid. Heads up people!
The lighting feels flat to me - and I don't know if that's because of the white background, blonde hair, or a combination of the two. I'm also not competent enough to understand why that's the case, but I know I struggled to "nicely" light my subjects with a small oblong softbox. Once I got a big one (150cm octa which is flippin' huge) it transformed my portrait work as it casts a lovely gentle light over my subjects. I just have a reflector to soften the shadow on the other side and Bob is my uncle. I'm really not an expert here though and there are other forum members who are much more competent, so I'll shut up about lighting.
I hope this doesn't come across as a bashing, I tried to be constructive. Like I said - take what you like etc etc...
