Find the SoaSE file location (most likely C:\Program Files\Stardock Games\Sins of a Solar Empire)...
Once in the game directory, go to the folder "Textures"...the name of the file you are looking for is "Startup_Loadscreen0.dds"...
If you do not have a program that can open this, I'd suggest downloading the Gimp...it is free and almost as good as Photoshop and similar programs...
The latest version of Gimp can be downloaded here for Windows...
You will need an Add-on to open DDS files, which can be found here...unzip the folder, and place the application file "dds" in the directory C:\Program Files\GIMP-2.0\lib\gimp\2.0\plug-ins or wherever it is you installed Gimp...
You should now be able to open the file "Startup_Loadscreen0.dds"...you may have to "Select a program from a list" as Windows will not likely recognize the file needs to be opened with Gimp...you'll probably have to browse for Gimp....the location of the executable file is C:\Program Files\GIMP-2.0\bin...you want to select the application that doesn't have the word "console" in its name...
If you have Entrenchment, there is another file with more conceptual art...once in the game directory, go to the "Entrenchment" folder and then the "Textures" folder inside that...the name of the file is "Startup_LoadscreenEntrenchment.dds"...
Hope this helps...