like how are they able to tell the difference

At the moment it doesn't look like they can. The paper is looking for two things that could make the objects "dark stars". The stars would look like point objects because they would be below JWST's angular resolution. The second is spectroscopic data which the writers don't have:

We note here that the spectra for those four objects, obtained in ref. 28, do not yet confidently identify any spectral lines, as they are too noisy (S/N ∼ 2). Follow-up spectroscopy is required in order to determine the presence of emission/absorption features paper. The paper's conclusion summarizes this:

we made predictions for the spectra of those SMDS candidates and suggested smoking gun signatures such as the He II λ1640 absorption line, a feature expected for all SMDSs but not for Pop III/II galaxies. We further note that the spectra of SMDS and early galaxies differ for wavelengths above ∼5 μm, so that future observatories (beyond JWST) might be able to differentiate the two types of objects in this way

In 2022, research on A. humeralis conducted by Dammika Wijekoon and Hemantha Wegiriya of the University of Ruhuna showed that male A. humeralis can look different in color and pattern, highlighting that there can be more secrets in the world of fireflies to be investigated.

The link they use is a OneDrive link when they could have just linked to researchgate

Links to at least a source:
Park solar probe
3D Maat Mons from Magellan data
Venus Express
Mariner 10

An image is only worth a thousand words if you know what you are looking at.

In the case of bees, Neonicotinoids are a particular problem.

I don't know if this helps but starting at roughly 39:00 of this Fermilabs lecture the lecturer mentions that lighter the dark matter particle is more wave like it behaves and so you have to imagine like a "fluid".