If you look at the stats from the games under Pochettino, we've been better in practically every aspect save points registered (which is pretty close on a per-game basis), and we've passed the eye test, as well. As mentioned above, he's not telling the players to shoot over from obvious chances, and it's something that we saw earlier in the year, as well...and saw for the second half of last season, for that matter. The common factor, I suspect, is the pressure of the situation; late last year, and now again, we face a race against a line, and every goal is vital. Early in this season, our players were facing the task of proving that they belonged at the Premier League level. Part of it is likely innate (our midfield scores a very healthy total, but they likely also receive an unusually-high percentage of the chances, and there isn't necessarily a natural finisher among them), part of it is the moment.
When I say 'practically', there's only one aspect that stands out: our work from set-pieces. Earlier in the year we were scoring from them at Stokian levels; now, we're hardly even getting deliveries in good areas. Whether it's not something that's being stressed enough in training or simply a down-swing, I have no clue...though any training focused on routines is largely irrelevant if the ball in either doesn't beat the first man, or ends up going to the opposite corner flag. Lallana did fairly good work previously, but he, Ramirez and Puncheon (who take the majority of them, though Jay is starting to get a few...which isn't necessarily ideal, given that he's not much for crossing) haven't been doing the job. Surprised that, given his crossing ability, Shaw isn't asked to take more of them...whether he's simply no good at it, or it's a philosophical decision to ensure that three defenders aren't forward, no clue.