In flexicontent image field is one of powerfull field, you can :

• upload image
• automatic rezize and optimisation (3 sizes)
• choose template output
• adding video player

In this site we create 2 fields, one for first image and one media galery

1. create a field
2. choose type image
3. assign to type
4. set option for number 

now you can select mode (db mode, specific folder, joomla)

in media tab you can allow video embed by same way

in viewing tab you can select

• size of thumbs (original, large, medium, small, admin)
• galery script peer view (desktop, smartphone)
• watermark