When adding the 
sign, Chopin probably omitted the base text to FE (see bars 15-16). The placement of the sign under the bottom stave could have resulted from the will to connect crescendo with the progression in the L.H. or due to lack of space between the staves. In the case of the latter, shifting the sign in GE2 (→GE3) would have been justified.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: GE revisions, Authentic corrections in GC
notation: Articulation, Accents, Hairpins