In FE (→GE,EE) the 
indication seems to be valid only from the semiquavers in the R.H. According to us, it is however highly unlikely for this indication not to include also the long resounding octave in the L.H. Therefore, we consider it as the notation's inaccuracy and in the main text we propose a relevant minor correction of the sign's placement. See also bar 45.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: Centrally placed marks
notation: Pitch