No real mystery with Miri; last year her skiing was up there with the best, but her shooting was shocking; even in most of her best performances (Fort Kent, Östersund) there were misses in there, and she'd be a guaranteed penalty loop in the relays (4 at Pokljuka, 2 at Antholz and 1 in the Worlds). I don't know about the weight, but she did a lot of working on her shooting in the off-season, because the skiing didn't need the same amount of work. At times we've seen the shooting work come off, but at other times it has been a real struggle, I think a lot of it is mental as after races she's talked about having shot perfectly in the training then lost it in the race. But this focus on the shooting has meant that her skiing has suffered from comparative neglect.
At the same time, much like last year the Russians gambled their season (unsuccessfully) on the Worlds, several of the Germans have built their season up towards their home Worlds; Arnd Peiffer, for example, had a very poor start to the season for a guy who was in the top 4 of the WC the year before but has come into his own since Oberhof. Miri's performances have been improving steadily this season, but not reaching the level that they did last year. It's not been a spectacular fall from grace à la Tarjei Bø, but I won't pretend it's not disappointing.