You need a default program to open the images. For me it depends upon what type of image it is. TIFF for me are opened by Photoshop, JPG & a few others by Preview, & I think QuickTime is the default of one or 2, etc.
So what you need to do is select a jpg file & right-click & choose open with ... choose your prefered program & tick the option for always open with. Do the same for TIFF & any other formats. It does work because I have done it for myself so previewing works fine with images.

For fast & easy access, go to your LW Library window, select Saved Files folder & press the Explore button. Sample image here: Using Library Explore button to access downld folder (click on link) & the folder will open up for you. Then select one of the picture files from there.