On that note, here's some interesting / related recent news in terms of a galaxy we have a hard time seeing: https://www.washingtonpost.com/news/speaking-of-science/wp/2...
This is the original paper for Dragonfly 44 https://arxiv.org/abs/1606.06291
There are a lot of question about the composition of that galaxy, and what makes it so dimm, but we need a lot more observations of that galaxy in order to even start asking the right questions including full spectral analysis from multiple observations and tools, correct redshifting and depth placement, ensuring that there is nothing in the way that could explain why it is so dim and many more other factors.
We also need to find other candidates of highly/ultra diffused galaxies in order to even start to try to figure out what is going on.