The carte de visite is by John Burton & Sons of Leicester, Derby, Birmingham & Burton-on-Trent. It shows a large group of unidentified adults, seated and standing in the garden of a large house. The portrait demonstrates one of the big disadvantages in the use of cartes de visite for large group portraits, i.e. that the physical limitations of the format meant it was often difficult to see much detail of the individual subjects.
The reverse of the card mount includes the words, "Sole Photographer to the Shakspere [sic] Tercentenary Festival, Stratford-upon-Avon 1864."
The firm of Burton & Sons advertised their "commodious gallery adjoining the pavilion" in the Birmingham Daily Post on 5 April 1864 (see image above, © British Library & courtesy of Gale CENGAGE database). The three hundredth anniversary of the birthday of William Shakespeare was celebrated at Stratford-upon-Avon on 23 April 1864. The brewer Edward Fordham Flower built a "special pavilion in which a banquet, a fancy dress ball, concerts, and performances of the plays took place." Burton & Sons obviously took advantage of the occasion by offering for sale a recently published "Series of Shakespearean Views," as well as taking the usual "carte de visite and other portraits."
The firm of John Burton & Sons had originally started in Leicester, possibly as early as 1858, and opened a branch studio under the name "John Burton, Sons & Co." or "Burton & Compy." in mid-1862. The branch remained in business until at least June 1865, and partnership between John Burton, his sons Alfred Henry Burton, Walter John Burton, and Oliver Burton and one Thomas Thorpe, was officially dissolved in May 1866 (Source: Birmingham Daily Post, 3 Jul 1862, 22 Jun 1865 & 7 May 1866).
Although not actually taken in Birmingham, the mention of the Birmingham premises on the card mount suggests that the photo was taken during, or shortly after, the period that it was open. Combined with the mention of the Shakespeare Tercentenary, this indicates a date of c. 1864-1866. The clothing and hair styles on the subjects more or less agrees with this date range. Some of the women appear to be dressed as bride and bridesmaids, although the picture is not clear enough to see which are which.