Is This Spice/K2?

No. The compounds that are spice/k2 are structurally unrelated to compounds like HHC, THC, CBG, CBN and so on which are classical cannabinoid benzopyrans.

Here is a photo of the synthetic indole based cannabinoids that went into those spice/k2 blends, their structures compared to classical cannabinoid benzopyrans, which is the structural class of drugs that THC, CBN, HHC, THCP belong to :  https://i.imgur.com/6d21TpF.jpg

Those types of synthetic cannabinoids have nothing structurally in common with the benzopyran cannabinoids in cannabis besides the alkyl tail and the fact that they can activate the endocannabinoid receptors.

Here is some research into why (indoles, pyrroles, indenes and related based cannabinoids and so on) are more dangerous compared to classical cannabinoids: https://pubmed.ncbi.nlm.nih.gov/15974991/ and https://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072008000100013