Well, to give the devil her due, she can consistently argue that she won a plurality of the popular vote and will likely go to her grave thinking she is the "rightful" 45th President of the USA.
IMO what she is trying to justify in this (new?) angle of approach is her failure to also win the Electoral College tally.
I find it interesting that many politicians, and their followers, assert both that there was no voter fraud in the areas they won, but there was voter fraud in the arenas they lost. She is not the only one who does this.
IMO it is more likely than not voter fraud has occurred in these United States, although I currently limit it to absentee balloting and possibly those locales still using paper votes (ala "hanging chads"). IMO an argument can be made, especially when it comes to the elderly in senior care facilities, that caregivers can and do "influence" if not outright "cheat" when promising to handle the votes of senior absentee ballots.
But in the main, I don't think such actions carry all that much effect. It seems Hillary is arguing that Republicans concocted some shenanigans in those swing States to suppress votes. That she actually won, despite the recounts that were conducted in several locales, those electoral votes. I find this especially funny when she was the one arguing it could not happen when she was secure in her knowledge of victory pre-election, and it was Trump who argued otherwise before he won.
To me it is simply a refusal to accept reality. Much like many who expected her to win, scream and emoted to the sky when she lost, then took up "the resistance" to undo the election results by any means necessary thereafter. Just a juvenile reaction ala "sore loser syndrome."