This is a custom portfolio caption, in the post editor add your custom text to the custom textarea labelled 'Portfolio Caption'.

This is a ‘Image Type Portfolio’. You can use this type of portfolio to display your images on a page. To create a new portfolio post using the ‘Image Type’ navigate to ‘Portfolios – Add New’ and select ‘Image’ from the ‘Portfolio Detail Settings’ below the portfolio post editor.

You then need to upload your desired images to this portfolio item, click ‘Add Media’ and select the images you wish to upload. Once uploaded, do not insert the images, simply close the upload screen. This theme will automatically grab the uploaded images.