The occasion: US President Calvin Coolidge congratulating Washington Senator ace pitcher Walter Johnson on winning the 1924 American League baseball championship. At a distance, the first thing to notice is the sea of straw boater hats. If you click on the image for the hi-res version (and click again to magnify), you'll notice a few more details on individuals such as the prevalence of natural shoulder suit jackets and one or two button cuffs.
President Coolidge (center, wearing straw boater) is wearing a single-breasted jacket in a light colored wool featuring what I call a rounded peak lapel (or 'clover peak lapel'), in which the tips of the lapel and collar are rounded. It looks very close to being a Tautz lapel but it's difficult to say whether the top of the lapel is horizontal.
The man standing in profile behind Johnson's left arm also appears to be wearing a light-colored wool jacket with a one-button cuff and what looks to be a lapped seam on the sleeve. Or is it another type of seam? Tailors and other folks in the trade feel free to weigh in.
Finally, behind him is another man who is wearing a boater hat and bow-tie. What's unusual is the lapel on his jacket where the notch opens wider and lower than modern notch lapels - somewhat similar to a cran necker style lapel though not quite.
All in all, despite the apparent similarity of appearances at an initial glance, we see in closer detail some interesting divergence in the details.