The additional 
sign, placed in FE (→EE) between the staves, seems to be added during a proofreading, thus correct. The hairpins could refer to the R.H., which would cause problems (crescendo on a long note), or to the left one, where they would double the sign placed under the semiquavers. Due to this fact, we think that the most likely explanation is the following: the sign put in A under the semiquavers in the L.H. was erroneously reproduced in FE over them. In the last proofreading of FE (not included in GE) Chopin added the second under the L.H., confirming his intention of providing the progression of semiquavers with this sign. Therefore, in the main text we give only the hairpins of A.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: Inaccuracies in FE, Authentic corrections of FE
notation: Articulation, Accents, Hairpins