The picture dates to around 1891-1893;
The 'dinner plate' sized hat sometimes called a 'platter hat', worn flatly a top the head is typical of the 1890s (though hat styles didn't change too radically during this decade);
The fashion plate in comparison is from 1895 - however like I said - hat styles didn't change all too much during the 1890s and hence can be very misleading in finding the exact date to a picture.
The Fashion Plate is from 'Le Moniteur de la Mode' and dated 1891. The early 1890s favoured hats with a wider brim at the front; in some ways it is a similar shape to a spoon bonnet - just laid flat on the head!
The bodice on the right is an extant example dated to around 1891-1893. The collar comes in at the front in a almost 'v' split swoop/at an angle - which you can just about see in the photo; in comparison to the early Edwardian bodices which favoured a full circle collar which closed at the back.
Her sleeves are also a tell-tale sign;
The high, gathered sleeve cap is stylistic of the early 1890s...
On the right is an extant 1891 dress; I have circled on the right ladys shoulder where you can just about see the same pleating.
The lady on the left has a button up plastron; a very common feature seen in Early 1890s bodices and follows on from the late 1880s fashion.
Again you can see the similarity in the collars, which are split in the front rather then button up at the back like later 1890s bodices.
Unfortunately I cannot help with the sashes; a few of the men I believe are wearing 'stoles' (you can just about see a passementerie tassel trim), but since I'm not religious I don't know the significance of them... I'll do some more digging for you.
Hope this helps.
