Look at the railing on the wall, it is twice as thick on one side than the other. It isn't down to one machine either- I checked on all my laptops, my desktop, even my PS4 and it shows the same.
It's like one side they accidentally fudged a number to where it doubled the thickness rather than keep it uniform and it shows on all floors in any mist medium I enter- I don't see it in my friend's goblet or lavender bed's medium, just mist.
It is clearly shown that way in the red circle in the pictures.

Also as someone mentioned, snap grid is just that, it snaps to the HOUSING grid, meaning furnishing would have 0 impact on that but rather how they offset the grid layout itself- this is so things can be "properly lined up"
The description itself even reads "Toggle grid snap on/off"

The stuff being complained about is something that would be noticed if you are picky as hell on this sort of thing, and having had all 3 types of mediums I notice it more with mist than the other two. It's just simply the house on grid mappings are slightly off and distorted.