That definitely looks weird, I will not even consider putting one in!!
If it was done by lexus then that might be the only way. Perhaps better to go with after market. Is it possible those 2 metal plates are needed so the bar does not block the kick sensor?
I recall reading somewhere that the hybrid models aren't built for towing (though they advertise 1500kg towing capacity) so perhaps Lexus did not consider the aesthetics of putting one in.
Fortunately my 2007 RX 350 still has the grant to tow 🙂.