I believe that sometimes this instruction can be paired with an SQI instruction which is looking for the appropriate conditions to advance to the next step (or position using the instruction parameter)
Irrespective of whether an SQO is paired with an SQI, each of them will require a false-to-true transition to make it advance to the next "index".
This is actually the case for nearly all instructions that have "Control" bits associated with them.
The control bits are used (amongst other things), to remember the last state of the rung, in most cases that is an "Enable" (.EN) bit, to determine if the rung has gone false-to-true.
Counters have 2 "Enable" bits, .CU (Count Up Enable), and .CD (Count Down Enable).
Remember that, in the PLC world, each and every instruction only knows one thing, the current state of the rung, true or false, when it is executed. They have absolutely no knowledge of what precedes them, or follows them, they just receive the "Rung Logic Continuity" as an input parameter (the "Enable_In"), and acts on the state of that accordingly. The "Enable_In" state is passed on to the next instruction as the "Enable_Out", mirroring the input state, so that following instructions can see the Rung Logic Continuity, true or false.
For this reason we can always fool an instruction into thinking the rung has changed state false-to-true, by resetting its "Enable_Out" bit anywhere else in the logic. The next scan of the instruction, assuming Enable_In is true, determines that since "Enable_Out" is false, the rung will appear to have changed state, false to true, even though it actually hasn't.
If a programmer wants a "controlled" instruction to execute every time it is scanned, it is quite common to see an OTU of the instruction's "Enable_Out" either in front of, or behind, the instruction.
Timers are an exception to this false-to-true "rule", timers being "Enabled" do not stop the instruction working each and every scan, for obvious reasons.