I would need to know more about their temperaments/personalities. I'd want more pictures of them, as well (stacked to see how they're built). Videos of them interacting with their siblings, if I couldn't meet them in person.
That said, I have never picked my puppies out. My breeder knows my dogs and situation, and has always picked the perfect match for us.
I would look at proper health testing (esp. for DCM, and that means holter and echo done, within the last year at least) long before I'd be concerned about a photo. I'd also look at longevity in bloodlines and what those bloodlines are in relation to DCM.
It's very odd that those are the photos that they sent you. As said above, I'd want to see stacked photos to try and judge conformation as best as possible from a photo.
I'd also be concerned that the breeder is allowing you to pick a puppy from a photo. Most reputable breeders pick the puppies for the buyers based on their living situation since they are with the puppies 24/7 and know their personalities.
Both of these would be a red flag. I'd suggest purchasing from another breeder.
For what it's worth, it is nice they tested for DCM1 & DCM2, but those tests don't tell us anything about whether or not a Doberman will get DCM in their lifetime. They are simply tools for research at this point. I would want to see annual echocardiogram and annual holter results for both parents to see how their hearts are actually functioning. There is a bevvy of other testing that should be done as well.
I can't imagine how on earth you'd pick one based on these photos. They won't look like this at 8 weeks, anyway.