With/out the ...to for the respective subcommands are essentially the same when source is a directory.
When source is a file
Subcommand is copy/move
A folder titled after the file's name, including extension, will house the specified file under the destination's directory.
Subcommand is copyto/moveto
File will copy to the destination's directory.
Examples
Subcommand is copy/move
Source: REMOTE:foo/test.txt
Destination: REMOTE:foo/bar/test.txt/test.txt
Subcommand is copyto/moveto
Source: REMOTE:foo/test.txt
Destination: REMOTE:foo/bar/test.txt
Notable
File/folder names can also be changed with either ...to for their respective subcommands. The folder will be titled with the new name when source is a file for the copy/move subcommands. Example with old-baz.txt as follows:
REMOTE:foo/old-baz.txt changes to REMOTE:foo/bar/new-baz.txt/old-baz.txt