Hi Johan -
I would agree this is probably a real young male LT that wasn't worried about how he buttoned his coat. Too bad we don't have more info about where the photo was taken or what unit it was. However comparing the Bundesarchiv photo with the known photo of Lt Whittle shows some similarities between the two individuals - especially the nose (I wish I had facial recognition software). I also noticed that in the Bundesarchiv photo that appears to be the only officer in the group which would support the conclusion that this a newly surrendered group. And they all wear their steel pots - probably not something that would happen once they got to their Stalag.
So I started looking for anything that would support the conclusion that the Bundesarchiv photo shows Lt Whittle sometime in Dec 44 or Jan 45 knowing that she was part of a prisoner exchange 25 Jan 45. I found this article
about an enlisted airman who was also imprisoned at Luft Stalag IX, camp 9C near Erfurt. Those on the repatriation list were moved to Stalag 4D at Annaburg by train around 1 Nov 44 where they stayed until 15 Jan 45 before moving by train to Switzerland. Holman says he arrived in Switzerland 20 Jan 45. Admitedly there is a few day difference that can't be explained.
As an aside, the prisoner exchange that officially occured 25 Jan 45 included approx 135 Jewish prisoner from Berden that held passposts from North and South America and about 130 US servicemembers. In exchange a group of Germans were repatriated from the US to Germany including some that were held in US detention centers. In some cases, the German repats were subsequently imprisoned and/or interrogated/beaten by German military per this article
Too bad we don't have Lt Whittle's diary. It would be an interesting story.