Mystery Monday - Unidentified Rochester, NY Woman

These two cabinet card photographs are obviously of the same woman from Rochester, New York. What is interesting to me is that although taken by the same photographer, I am not totally certain that these photos were taken on the same day. She is wearing the same dress but there are some slight differences in the two pictures if one cares to look closely.  In the first picture our lovely subject is wearing the typical 1880's bustled dress with fitted bodice.  The bodice has a number of buttons, around twenty, down the pleated front. At her neck she is wearing a pin/brooch in the shape of a letter "D" which makes you wonder if her name perhaps started with that letter.  She also has white lace jutting out from under the top of the neckline of her dress.  This photograph is a full-figure pose and she is standing with her hand resting on a studio prop faux, wooden chair; behind her the backdrop is a large tree trunk.  She is wearing a curly hairstyle that was so popular with women in the mid 1880's.

The second photograph is a bust pose in which we can only see the top half of her dress but it is obviously the same dress.  If you look closely however, you will see that there is no lace sticking out of the neckline as in the first photo. Additionally, in the photo she is wearing a different brooch at her neck in the shape of  flower with stem and leaf.  She is also wearing a pair of small drop earrings which I am not sure if she is wearing them or not in photograph number one. She is wearing a necklace of some sort in the first photo with a square-shaped charm that is sticking out of her buttons mid-way down the placket of her bodice.  I believe she is also wearing this in the second photo.  Her hairstyle looks very much the same in both photographs.

My question about our mystery woman would be, did she have these photos taken the same day and change accessories or were they perhaps taken some time apart and she wore the same dress? The photographer is a bit of a mystery as well - the front of the card says "Pomeroy Gallery" while the back says McMahon & Nelson.  I did find a mention of McMahon & Nelson in the 1887 Rochester, New York City Directory.  Due to certain clues in these pictures this is also about the time I would date these photos, 1885 - 1888.