A simply lovely Thursday for the start of The Turn! I figured out what was going on about 1/3 of the way through solving.
How many of us had IMAGE at 1A: Thumbnail, and then took it out when filling in 1D: Part of a sun salutation, in yoga ([DOWNARROW]WARDFACINGDOG)? I tried upWARDFACINGDOG first, which, if you've ever owned a dog, is the slightly less cute dog position. I worked through the full side of the west and started up the middle, when I hit 19A: Hosp. hookups (IVS). That IVT in the middle gave me pause, and then I saw it.
It's just the sort of theme that can only work with your theme answers in the long down positions. For those who are unaware (or who maybe just never thought much about it), any puzzle can be flipped across the axis of symmetry from NW to SE and still work. So there is only convention keeping our theme answers as the long acrosses.
Here, IV becomes a down arrow, replacing the word "down" in four common phrases. Thus GOT[DOWNARROW]TOBUSINESS, TRICKLE[DOWNARROW]THEORY, and KEEPSONTHE[DOWNARROW]LOW. Also very nice is how the arrow steadily moves down the grid as you go from left to right.
|BAMBI and friends|
Some fun clues today:
34A: Hamilton producers? (ATMS). Cute.
41D: Muppet whose self-identified species is "Whatever" (GONZO) - agreed. Don't let them pigeonhole you, Gonzo, and your pet hens.
38D: Sight seers (EYES). Indeed they are.