The work proposes that because responses to difference visual stimuli show the same haemodynamic spatiotemporal response in memory areas, the actual memories must share a common representation. This is debatable since we know that localized spatiotemporal responses reflect the variability in the vascular tree and blood flow and volume, regardless of the experiment at hand [see 1 for a discussion]. To dare to claim that effects could be neuronal one needs to run a bunch of extra control experiments (vascular reactivity mapping / breathhold hypercapnic challenges, resting-state imaging as a control dataset), none of which were conducted in the proposed work.
This is known to MR physicists, but hasn't clicked in yet within departments of cognitive neuroscience.
[1] https://www.frontiersin.org/articles/10.3389/fnins.2020.5960...