It appears the dimensions are incorrect. The last one of 4" should be around 14" to 17", working backwards from the volume. Could you please check and confirm?
Zappo's website had some specs on the 3 sizes that made sense, although with some confusing anomalies.
(small size weighed the most, mention of handles on the medium but not when describing other sizes...)
S: 23 w x 10 d x 16 h, strap length 40, strap drop 19, wt 1 lb 8 oz
M: 25 w x 15 d x 14 h, strap length 39.5, strap drop 10.5, handle length 6.75, handle drop 1.5, wt 1 lb 3 oz
(also mentioned a "top width" on this model of 36.5, this wider opening at top is evident in photos)
L: 27 w x 15 d x 17 h, strap length 38.5, strap drop 23, wt 1 lb 6 oz
BTW: what is "strap drop"?
with the strap fully extended, it's the length from the apex of the curve, to the top of the actual bag... something you usually measure for purses so you know where it hangs when on your shoulder.