I dunno if this is what it’s talking about (also keep in mind there are probably multiple kinds of these cells).
VIP (vasoactive etc.) cells inhibit martinotti cells. Martinotti cells inhibit the apical dendrites of pyramidal cells, and receive input from pyramidal cells. Martinotti cells receive facilitating synaptic input, possibly selecting for bursts (or something else, like persistent activity or a firing rate code, I dunno). So overall, VIP cells might tune-down competition for burst-mode firing in pyramidal cells. They can be activated by motor cortex, or by subcortex during running, and might do spotlight attention*.
*(https://www.sciencedirect.com/science/article/pii/S2211124721000875, https://www.sciencedirect.com/science/article/pii/S0092867414001445, and https://www.jneurosci.org/content/jneuro/36/12/3471.full.pdf. As part of a deeper dive also see “Nonlinear dendritic integration of sensory and motor input during an active sensing task,” there’s a free pdf on google scholar, and L5tt cells are attentional (paper summaries)).