Probably not, as it results in this error:
Error setting attribute: Setting attribute standard::symbolic-icon not supported
You can list the writeable attributes of a folder/file (e.g. $HOME, the users's home directory) by running:
gvfs-info -w $HOME
for this I get:
Settable attributes:
standard::symlink-target (bytestring)
time::access (uint64, Keep with file when moved)
time::access-usec (uint32, Keep with file when moved)
time::modified (uint64, Copy with file, Keep with file when moved)
time::modified-usec (uint32, Copy with file, Keep with file when moved)
unix::gid (uint32, Keep with file when moved)
unix::mode (uint32, Copy with file, Keep with file when moved)
unix::uid (uint32, Keep with file when moved)
Writable attribute namespaces:
metadata (string, Copy with file, Keep with file when moved)
xattr (string, Copy with file, Keep with file when moved)
xattr-sys (string, Keep with file when moved)
For the standard folder icon, this is set by metadata::custom-icon (or whatever), which comes under the metadata name-space. Any other attributes that aren't listed are not writeable - including standard::symbolic-icon. N.B. creating metadata::symbolic-icon or similar and restarting nautilus seems to have no effect either
Sources/More info