When I went for a scan at 13 weeks the woman said I was “too chubby” for the external one and did an internal one to get a better photo. But it could also be their equipment because I had an external one at 7 weeks and we clearly saw the little bean and heartbeat. They were at different places in different countries. So I reckon the place at 13 weeks didn’t have a great machine for external.
Looks like it’s an older machine photo, 2kg wouldn’t make much difference (unless every bit of it was fat and all in between the baby and the scanner) but likely not. I’d say it looks like the difference between my nhs and my private scans where the private hospitals have the latest equipment. I wouldn’t get hung up on your weight as it’s very unlikely the issue. If you can I’d book a private scan and enjoy the much better quality photos you’ll get from that xx