Validation corresponds to a single inference pass in neural network terms. (which is fast)
Mining is much harder and involves millions or more of inferences passes (depending on difficulty).\
In other words, this is not a new Proof-of-work algorithm.
It's still the Hashcash POW used in Bitcoin, that computes a deterministic value for any given block header using some hash function, and compares it against a target value that's inversely proportional to difficulty.
The difference is in the hash function used for Hashcash. Instead of Bitcoin's SHA256d, this proposal uses a tensor (i.e. matrix multiplication) based hash function.
It's not an asymmetric PoW like Cuckoo Cycle or Equihash, where verification differs from (and is WAY faster than) a solution attempt.