Same option in views\default\forms\photos\admin\settings\activity.php of your plugin:

echo elgg_view('input/select', array(
    'name' => 'params[river_thumbnails_size]',
    'options_values' => array(
        'small' => elgg_echo('tidypics:option:river_comments_thumbnails_small'),
        'tiny' => elgg_echo('tidypics:option:river_comments_thumbnails_tiny')
    ),
    'value' => $plugin->river_thumbnails_size,
));

Change 'tiny' on 'large' in there.

The River feed is still coming up album thumbnail size... let me try some experiments...

Change one or both instances of "Tiny"?

echo '</div>';
echo '<div>';
echo elgg_echo('tidypics:settings:river_thumbnails_size') . ': ';
echo elgg_view('input/select', array(
    'name' => 'params[river_thumbnails_size]',
    'options_values' => array(
        'small' => elgg_echo('tidypics:option:river_comments_thumbnails_small'),
        'large' => elgg_echo('tidypics:option:river_comments_thumbnails_large')
    ),
    'value' => $plugin->river_thumbnails_size,
));

All styles inside this file:

vendors\jquery\colorbox\theme\colorbox.css

Elgg 1.12

Thanks so much! :)

so change

'content' => $excerpt,

for

'content' => $blog->description

gotcha TYVM!

added comma

'content' => $blog->description,

will try making new blog for posting soon

You can try to use $body instead of $blog->description also.