REALLY? This “caption” would totally be submitted to shit my students write if I got this in a student exam or paper. Try, “her puffy sleeves indicate that it is 1897 and she is in the pink of fashion”! The mourning (if indeed it is, which I am not convinced of, because people on Tumblr seem determined to identify every lady photographed in B+W as wearing mourning) comes from her bodice have crepe.
One of my biggest pet peeves is the assumption that black + Victorian = mourning. If anything, her sleeves would probably be reduced for mourning, and she would be wearing a mourning bonnet and corresponding veil. Black was actually a very popular color for formal wear. Also, if you look closely, you can see the dress isn’t even black.