According to the personnel given in the link you provide, this famous "floating heads" photograph can be fairly accurately dated to February-March 1927, since it includes both Don Murray and Danny Polo. Don Murray developed "trenchmouth" (a severe form of gingivitis, which he had apparently been suffering from for several weeks) in January 1927 and was replaced by Jimmy Dorsey. Dorsey left on February 1st and was replaced by Danny Polo. Murray rejoined the Goldkette band "around" February 24th according to Sudhalter and Evans. Polo stayed on until late March 1927.
According to the personnel given, the sax section is FIVE strong - Don Murray, Danny Polo, Doc Ryker, Jack McGay and Frank Trumbauer. However, according to all other available sources, the band's sax section was never more than four strong. Indeed, it was only four strong because Danny Polo stayed on for a few weeks; after Polo left, the band reverted to the established triumvirate of Ryker, Murray and Trumbauer. According to Sudhalter and Evans in Bix: Man And Legend, the addition of Polo allowed Trumbauer "more time to front the band" (Trumbauer being the band's nominal leader). This no doubt explains why Trumbauer is standing in the photo - it demonstrates his position as leader.
The above brings us to question the "fifth" member of the sax team, as shown in the photo, Jack McGay. I have put fifth in quote marks because I do not think that McGay was a member of the sax team: he was a violin player who I think was simply sitting in the place that Trumbauer normally occupied, whilst Trumbauer stood for the photo. The saxes in front of McGay are an alto sax and a C melody sax - and those are of course the two instruments one associates with Frank Trumbauer. Granted that there is also a soprano sax present, but sax players of the period would have been required to double on soprano, so there's nothing unusual there. Same goes for the clarinet.
Note that on page 25 of the following booklet (published in 1930):-
….there is a section about Jack McGay that states "Jack plays the violin" whilst leading a Goldkette band. It doesn't mention anything about him playing the saxophone.
As far as I know, to date no-one has been able to ascertain where this "floating heads" photo was taken. It certainly wasn't taken at the Graystone Ballroom - the bandstand is far too small and the band are almost crammed into the limited space! So where was it taken? Mention of Jack McGay got me thinking. Detroit newspaper reports dating from 1930 state that McGay led a Goldkette band at the Book-Cadillac Hotel. Though I cannot find any historic evidence to suggest that McGay was leading and/or playing in a dance band at the Book-Cadillac in early 1927, we do know for certain that Goldkette had supplied bands for the hotel dating back to its opening date on Monday, December 8th, 1924, and these certainly included violinists, as recorded examples of the 1926 Book-Cadillac band led by Owen A. Bartlett clearly demonstrate.
The above connection, albeit seemingly tenuous, between Goldkette, Jack McGay and the Book-Cadillac Hotel led to me searching through 1920s photos of the interior of the Book-Cadillac Hotel to see if there might something more substantial that could help to pin down where this "floating heads" photo was taken. How about those distinctive palm leaves seen in the Goldkette photo, for instance? Photos of the main ballroom failed to provide any obvious clues but then, bingo, I came across this photograph of the Italian Garden at the Book-Cadillac Hotel:-
Here was an obvious connection - those distinctive palm leaves! These are also clearly seen in the "floating heads" photo.
There is further evidence that the Goldkette band "floating heads" photograph was taken in the Italian Garden at the Book-Cadillac Hotel:-
Firstly, it should be noted that according to his Wikipedia entry (and other sources), Jean Goldkette's entertainment company, 'Jean Goldkette's Orchestras and Attractions', was based not at the Goldkette Ballroom but at the Book-Cadillac Hotel.
Secondly, as has already been stated, Goldkette had a long-term contract, starting in December 1924, to supply dance bands to the Book-Cadillac Hotel. Moreover, there were broadcasting facilities at the Book-Cadillac, so Goldkette's famous 'Victor Recording Orchestra' with Bix and Tram could continue to broadcast over WJR during any engagements at the hotel.
Thirdly, and most importantly, according to Sudhalter and Evans, on February 22nd, 1927, Jean Goldkette and his Victor Recording Orchestra (including Bix) provided "dance music for the Bohemians (Musicians Club of Detroit) program at the Grand Ballroom of the Book-Cadillac Hotel starting at 6.30 p.m. Jean Goldkette, a club member, was chairman of the ballroom music committee."
I think it likely that, given the above evidence, Jean Goldkette's Victor Recording Orchestra played at the Italian Garden of the Book-Cadillac Hotel on or around the same date that it provided the music for the Bohemians ball in the Grand Ballroom, namely Tuesday, February 22nd, 1927. The band may very well have played out the week at the Hotel, though I have no direct evidence for this. It should be noted that Don Murray returned to the Goldkette band "around" February 24th, so it is possible that he rejoined it a few days earlier, in time for the Bohemians ball.
Furthermore, if Jack McGay was already playing in and/or directing a Goldkette band at the Book-Cadillac Hotel, that would explain his presence in the photo rather than Eddie Sheasby's.
If my theory is correct, then the Goldkette band "floating heads" photo was taken on the bandstand at the Italian Garden in the Book-Cadillac Hotel, during the week commencing Monday February 21st, 1927. For this engagement, Goldkette's Victor Recording Orchestra was probably led by violinist Jack McGay, who is known to have led other Goldkette-organised bands at the Book-Cadillac Hotel.
Incidentally, the Italian Garden was established in 1924 and was recently refurbished - without the palm leaves! - at considerable cost.