Here is a plot of the mean surface brightness of a galaxy vs. its absolute magnitude (its luminosity) for the known galaxies within 10 Mpc;
It is screamingly obvious that mean surface brightness gets ever lower, with progressively decreased galaxy luminosity.
In other words, the fainter the galaxy, the more scattered and less significant are its stars;
yet gravity still holds together the stars of these least-luminous and "powder puff like" galaxies. Hence the idea that the least luminous galaxies have the most insubstantial amount of stars, but instead are totally dominated by dark matter.
At the very lowest Galaxy Luminosity in this plot, perhaps we will find the fabled and often predicted "dark galaxies"......so keep imaging deeper, Mike!