Both the interior and exterior of the Ayer Mansion were unusually progressive for turn-of-thecentury Boston and would have distinguished the Ayers from their contemporaries as forwardlooking and worldly patrons. The street elevation of the light-colored granite-faced house, with its smooth, flat surfaces ornamented by bands of mosaic panels, introduced a modernizing aesthetic to Boston's Back Bay. The back Bay, an area studied by Bainbridge Bunting, contained "after 1895 only one large… house, 395 Commonwealth Avenue,… built in a nonhistoric style." Douglass Shand-Tucci also concluded that the building was the first in the area to display "progressive" tendencies. The austere, white form, with smooth surfaces punctuated by windows devoid of surrounds and accents of brilliant color, does indeed resemble designs by Joseph Olbrich in Austria and Germany or Charles H. Townsend in England more than anything in Boston at the time.
In the entrance hall of the Ayer Mansion, Tiffany combined mosaics and stained glass transform an ordinary hall into a sumptuous, luminous stage set, perhaps intended for amateur theatricals and musicals. Although Tiffany employed dozens of craftsmen and designers by 1900, he remained very much involved in the conceptual design and in reviewing elements of the design. As in his earliest work, the artist has a hand in each component as well as in the overall composition, Visitors to the Ayer Mansion entrance hall are surrounded by what Frelinghuysen has described as "a visual feast of color, light and texture."
The Ayer Mansion entrance hall, with its white marble wainscoting, mosaic stair risers, and glass mosaics in the apse-like stair, recalls Tiffany's famous chapel at the Columbian Exposition, Chicago, 1893. Originally intended as a sort of advertisement for his work in mosaic in glass, Tiffany "came to regard (the chapel) as his artistic chef d'ouvre." This chapel, seen by 1.4 million visitors and awarded 54 medals, was the "pinnacle of his work" in the genre of mosaic. Some of the chapel elements remain at the Morse Museum of American Art in Winter Park, Florida. At the Ayer Mansion, a comparable interior can be experienced in its entirety.