Along the lines of what Beedeetee said.
Here is a bit of info Walt Wright shared with me on a simular subject.
Clues identified before:
...SS cells are normally less in number than swarm cells. SS cells can range from 1 to about 10. My rule of thumb is 6 or less on any level as the brood nest expands upward, but have occasionally seen more.
...Swarm cells normally exceed 20, but sometimes are less in hard times.
...SS cells are normally roughly about the same stage of devopment, while swarm cells will often range from egg to capped. Expanding on that just a bit, the colony in SS is in a hurry. Having decided that the Q needs replacing, they move out smartly and populate cells in a short period. The swarming colony will stretch out population of cells to provide backup cells in the event of primary Q loss.
Adding a few more notes: (See article in POV on the subject)
SS cells are generally built on bases built in advance of the need. And provided for just that purpose. Those advance bases for cups are not normally provided within the existing Q travel areas. A favorite place is on the bottom of the feed pollen frame. (within the warmed cluster area but outside the queen's traveled area)
Although it may not be universal, normally SS cells are built on the left side from the back of hives that face south. (warmed by morning sun)
Tilt the box with Q cells and get an accurate assessment. If the frames with cells are filled with brood, think swarm. If the frames with cells are mostly pollen, think SS.
What it mentioned is based on a "normal" started hive. On a fresh cutout I would almost always think SS. They have been thru a lot of stress. Typically they blame the queen for this stress and SS her.