Firstly, Flipkens has been, in the last year or so, in her career best form, and she is ranked 8 places above Mona, so this hardly is an upset, although it would be considered a winnable match.
We also didn't see the match so we are lacking something in being sure exactly what happened.
There certainly seems to be a worrying trend in Mona's matches though. After she missed the chances to break at 4-4 in the first set, she lost many games easily. She seems to become a bit negative if things start slipping away.
A similar pattern could be seen in Bojana's match today against Julia. After losing the key game at 4-5 when she had just broken Julia and was back on serve, the match slipped away from her, albeit a bit more slowly than in Mona's match. Both of these girls have been losing a lot of matches recently and have unknowingly developed some kind of losing habit which manifests at key moments in matches and causes momentum to get away from them.
This is a difficult situation for Mona.
Many things are open to speculation, but it is clear that the current situation is not working well enough for her and right now she does not seem capable of dealing with this problem by herself. She needs to have a way of stopping or at least slowing down the slide when her game slips away form her.
There is a certain mindset needed to compete at the highest level, and Mona is not doing it, and possibly some other things, right at the moment.
Of course it's theoretically possible for her to figure out how to remain in a competitive mindset under pressure by herself, but a bit of help would probably not go amiss.
Nonetheless she is still ranked 30 or close to it in the world and in my opinion every match is a good opportunity to break the losing habit. So I think she needs to keep playing. But before she steps out on court next time she needs to find her fighting mentality. She has to find a way of fighting back against opponents, against losing situations, against tiredness, against bad form. Sometimes when you are out on court and your game isn't working the way you want, you feel like you are your own worst enemy. It requires a kind of mental toughness to be able to battle not only your opponent but your own game. It's a necessary skill though because on some days your game is not your friend, but an adversary, and you still want to win on those days too.
Mona would have no problem fighting against even the toughest opponent if her game were her ally, as it was in some of her earlier matches some months ago. But when her game doesn't seem to be her friend anymore she starts to become mentally lost.
When you seem to have no allies on court, even your favourite shots are betraying you, you need to keep fighting, alone if necessary. Beat your opponent without your backhand, without your serve, without anything except will power. Even when your own mind seems to be your enemy, you still need to find a way to win or at the very least compete tough.
Maybe this was the difference in Fed Cup, where Mona felt she had allies. Also, it helped that Bojana was in poor form.
The other side of that coin is that if you are prone to bad form you need to become good at coaxing better tennis out of your game even when things seem to not be working. Some players are able to do that, they can be playing horribly but over a period of minutes they make adjustments and find a way to make the backhand, to make the return of serve.
You normally wouldn't think of Petra Kvitova as being an example of a good match player, she is so up and down, but she is very aware that even when playing horribly she might start finding her shots at some point, and she turns around a surprising number of matches after playing awful tennis. That's why she is number 8 despite her ability to play some of the worst tennis in existence. (I suspect that if she ever got in proper shape she could be significantly higher). Whereas when Mona starts to play badly you don't get the sense that she thinks she can find her tennis again. It seems that she starts to feel the situation is hopeless. Petra is surely worried when she starts bashing the ball miles out, but she keeps going in the hope that she will find the range again in time to turn the match.
I admit that Flipkens' game is designed to make it difficult for an opponent to establish a rhythm, as well.
Do we have any reports from people who saw it live?
I have always thought that Petra Kvitova is a phenomenol match player and i think she proved that when she played the biggest match of her life against Sharapova in Wimbledon 2011. I like how she keeps going for her shots with a clear determination, no matter her form or the scoreline. She is by no means a headcase, as some posters in GM say, she is just an inconsistent player. As quick as she can lose three or four games in a row by spraying errors, she can easily win the next five by finding her shots again. It seems that Petra has accepted the special nature of her game and this is why she is able to pull her game through with some sort of stoicism (the german word is "Gleichmut"), without giving anything away from her determination at the same time.
So i think you are absolutely right, Mona could (should) use Petra as a role model, as she needs to develop the same sort of basic trust to her game in order to be able to play with a similar kind of stoicism like Petra, especially when things go wrong in a match.
(On a side note: If Petra ever sorts out her fitness issues, i am quite sure she will be the one to seriously challenge Serena Williams.)