I should clarify, that Jörgen´s suggestion was Yellow-legged Gull, even if it´s hard to completely rule out Armenian. And naturally, a small female YLG would be the first choice at our latitude.. Any comments are welcome!

Interesting gull - but as Hans and Jörgen suggest michahellis would be far more the realistic (?) choice in this case. There seems to be nothing specific in these images that would point to armenicus for sure, or rule out a female short-billed michahellis, or perhaps something else for that matter.
How reliable is really the nostril character, seems on this bird to be slit-like, not the usually armenicus wider at the front like.
Primaries looks rather blackish and fresh for a 2cy at this time of year - atypically renewed? Obvious pale inner web of one of the inner primaries is interesting.
The first individualin in the blog Birding Kuwait 21/12 - 2/1 (where Hans partisipates) shows one individual - although taken much earlier than the Swedish one - that has a strong similarity in wear, pattern and jizz to the Swedish bird, mind the time difference.

http://kuwait20072008.blogspot.com/2007/12/christmas-eve.html

Not excluding armenicus (can´t from these images) but my money on a female looking michahellis, or something else perhaps? More images.

JanJ