Hello @elliot, thanks for your response!
Definitely it’s correct.
Just try to access here (the local url http://dev/spa/wp/wp-content/uploads/2014/02/02082_apeacefulscottishevening_2560x1440-120×60.jpg), and it’s ok!
For now, I’m using one of the default WP sizes (medium), and adjusting the size with css.
I’ll upload the project to the production server, and will test if it could be a local server problem (MAMP). Will post here the results.
Thanks