As you might have noticed, we can't normally put things on the new half-partitions, and yet how is that chronometer apparently resting on top of it? No table is tall and slender enough to fit inside those partitions. The answer is, it's a glitch - if you don't like glitches deal with it. I should be able to put my moogles wherever I damn well please.
The rules for placing tabletop items in "forbidden" places haven't changed much since 2.1, but with the addition of wall-mounted furniture being placed on partitions and the Riviera Wall Shelf, we now have the freedom to place objects pretty much anywhere in the room space where a partition can fit. The main caveat is if you want to place objects below the height of the bottom portion of a partition where the Wall Shelf can't go, you will have to use a shorter Table furnishing instead.
These instructions are for PC interfaces - Sorry but I don't own the game on PS3/PS4 to help you out here.
First, put down any standard partition (Riviera/Glade have more vertical space) and put the Riviera Wall Shelf on it. If you want it shorter than the shelf can go, just replace this whole thing with a shorter table like an Oasis Table (it doesn't go much shorter unfortunately).
Next, place your tabletop object on the Wall Shelf. Position your partition so your object is where you want it to be, and position the Wall Shelf so that it is flush with the surface you want to "place" your tabletop object on- you won't be able to adjust the position without starting from scratch so get it right (you will still be able to rotate it freely afterwards).
I have highlights turned on so that you can see highlighting the partition highlights all 3 grouped objects - wall, shelf, clock.
At this point, turn your "Toggle counter surface placement on/off" to OFF. This is a 2.2 change.
And now the magic: You want to select your tabletop object and move it away,but do not place it. Instead right-click to return it to its original position.
If you look closely, when I highlight the partition, the clock is not highlighted. I have "soft-broken" the connection the clock has with the wall/shelf combo but preserved its position. It will simply regroup back to normal if you do almost anything.
In order to permanently break the group connection, move the wall/shelf combo away and place it. The tabletop object should stay where you want it, and you can now safely remove the shelf and wall and turn the surface placement setting back on if you wish.
Note that all this does is preserve the spacial position of the clock to give the illusion that it's sitting on top of the half-partition. If I moved the half-partition away, the clock would be floating mid-air... which opens up even more possibilities (like that mog-house mid-air moogle you always wanted...)
Enjoy, and happy furnishing!