I rewatched the trailer for Little Dipper, and here's what I get:
Around 0:13 we see an old book by Gideon. #2 perhaps? This could mean in this episode, Dipper finally gets #2 or he learns that Gideon has the second book.
We also see Gideon holding a flashlight when they shrink, meaning the flashlight is what shrunk them. We also see him approaching Grunkle Stan with it, meaning he's going to shrink him.
We also see Soos in, what looks like, carpet, if you zoomed up close. The means he also shrink him, which means he might have shrunk Wendy.
EDIT:
Around 0:13 we see an old book by Gideon. #2 perhaps? This could mean in this episode, Dipper finally gets #2 or he learns that Gideon has the second book.
We also see Gideon holding a flashlight when they shrink, meaning the flashlight is what shrunk them. We also see him approaching Grunkle Stan with it, meaning he's going to shrink him.
We also see Soos in, what looks like, carpet, if you zoomed up close. The means he also shrink him, which means he might have shrunk Wendy.
EDIT:
Dipper feels self-conscious that Mabel is taller than him and is becoming the alpha twin, so he seeks out a magic way to grow himself the same height. Meanwhile, Lil' Gideon takes advantage of Dipper's and Mabel's height discrepancies.
