Your Home and category pages export as lists of truncated posts, or teasers. Category pages will list all teasers. The Home page will list the number of teasers you’ve entered into the BlogHome Control Panel (see here for details).
Teasers will appear on your exported webpage either as a single sheet separated by horizontal rules, or as floating cards (if you use the CARD) export option (details here).
Featured images will appear on the left with a max-width of 140px. To change their default size to something else, use the Image Size Widget.
To change this, go do the Directories Dash and change the value of .img-trunc (in the Image Sizes II Widget).