@Background Pony #A490  
Oh, I was #9B69 before.

@Background Pony #A490  
Yeah, I’m betting that’s a common thing. Of course, if she had been pissed about having garbage dumped all over her it’d be understandable.
 
Silly Lyra comics? I’d like to see a link to those.

@Background Pony #9B69  
OK, I was misremembering the PYHD scene, and you’re right about it. Bon Bon does give Fluttershy one mildly-annoyed glance before having her garbage dumped on her, but otherwise it’s her friend who’s the instigator.

@Background Pony #A490  
In “Putting Your Hoof Down,” a dirty look at Fluttershy after Flutters kicked the barges of trash she and her friend were pulling right onto them seems really understandable. It was her friend who was being rude; maybe her friend’s angrier lines before and after it all are remembered as hers because the “not amused” portrayal had already taken hold. But Bon Bon’s line, to her friend before Fluttershy showed up, was “Try one of your jokes out on me, I laugh at everything.” (It’s also the one where the shipping gets “OMG it’s semi canon!” wings; her saddlebag’s got Lyra’s CM.) So her biggest role before Slice of Life depicted her as very reasonable and harmless. Sense of humor despite a very unpleasant task, the one who isn’t rude to Fluttershy before and is least angry with her after the bridge incident, and just enjoys spending time with her (ahem) ‘best friend.’ It’s the episode that made me like her after not having known much about her outside the shipping until then.
 
But her being the straight mare to the antics of the others is an okay portrayal. But like you said, if not taken too far.

@Background Pony #9B69  
As long as it’s not taken too far, I like the “Bon Bon is not amused” trope, as I can empathize with a pony who’s had enough of the crazy shenanigans of Ponyvillans. (Ponyvillites? Ponyvillers?) And to be honest, she’s had at least couple of other appearances where she wasn’t a ray of sunshine, in “Green Isn’t Your Color” and “Putting Your Hoof Down”. Having said that, though, it’s awesome that she’s been given further depth, and that the fandom is incorporating it into its works.
 
Lyra’s human obsession is overworked (and seemingly has gotten more heavily referenced as time has gone on, despite other ponies adopting human-like sitting poses in episodes since “Dragonshy”), though it does still occasionally result in a funny drawing/comic. Personally, I’ve always been more fond of the “irrational exuberance” side of her personality, or anything vaguely related to or potentially derived from it, like the “Silly Lyra” comics.
 
And while I like LyraBon shipping, I hope this episode inspires more art and comics depicting them platonically, just because variety is nice.

Yeah. She did need some solo focus, and I really didn’t much like the portrayal of “she’s always pissed, ‘cause being annoyed when some kid tries to extort you clearly means you’re borderline evil.”
 
Of course, with Lyra it wasn’t much better. Sitting like a human in one blink-and-miss moment means humans are the only thing you’re capable of ever thinking about, right?
 
If you think about it, they both got the short end of the fanon stick. Derpy gets to be a mailmare, a mother, struggling with whatever condition the crossed eyes are interpreted as indicating, and Doctor Whooves’ companion.
 
Nothing’s wrong with that, but still. A little got made into a whole lot. If you knew the fanon but didn’t watch the show you’d think she was one of the mane six because of what we get from a crossed eyes. Which makes it sad when your favorite background pony gets such a one-note fanon portrayal.
 
Lyra, we know more about than we do many of the more prominent secondary characters. She hops around grinning like Pinkie, she lived in Canterlot at the same time as Twilight, she knows Cadence well enough to be a bridesmaid. A lot could be done with that… so naturally, her portrayal starts and ends with “hurrr humans.”
 
Bon Bon doesn’t have as much in this series, but she’s got a very fleshed-out past gen counterpart, and a cutie mark that makes it easy to work out what her career is. And the voices thing (to be fair, that saw some use in fan work for a while.) But nah, “I didn’t put those in my bag” makes her Skeletor. (She also hated the bad cider, but so did everyone else. Anybody who would want rocks in their cider, raise your hand! …well, it’d be a plus to Maud.)
 
Being shipped with the other gave each of them a second trait, which is a good thing, and awesome to see the writers supporting it. But anyway, I’m hoping two of my favorite background ponies will be treated a little better now by the world at large. And it’s great to see Bon Bon get something so awesome. She’s definitely not the less prominent of the two now.
 
Eh, didn’t mean to go on so much.

It’s nice we have a theme for Bon bon now, rather then her just being Lyra’s girlfriend pony.  
Not that I’m opposed to Lyra’s girlfriend pony status but I like that she has something for her own identity.