Simple test of how shortcode attributes are being formatted when HTML tags are used. This was an issue with WordPress 4.0-alpha-20140616 and has been addressed in the ticket: Shortcode Attributes with HTML Tags no longer working
[expand title="Test" trigclass="noarrow" alt="turtles one"]This is the content of the first image[/expand]
Test
This is the content of the first image
[expand title="<strong>Strong Test</strong>" trigclass="noarrow" alt="turtles one"]This is the content of the first image[/expand]
Strong Test
This is the content of the first image
[expand title="<img src='https://spacedonkey.de/wp-content/uploads/2012/09/ninja_turtles-150x150.jpg'/>" trigclass="noarrow" alt="turtles one"]This is the content of the first image[/expand]
This is the content of the first image