Did Alicia really wear a wedding scarf at the end of Senjou no Valkyria (Valkyria Chronicles)?
That picture of Alicia and Welkin is from OVA 9, or the epilogue from the story.

It's a screenshot of this OVA where the summery can be found on the official wikia page from Valkyria Chronicles here

It's marked as episode #35 at the bottem of the page