It's a decal. It was really easy to apply to the wall, just time consuming with all the little flying seeds. Here is a link where I bought it.
http://www.etsy.com/listing/60613176/dandelion-blowing-in-the-wind-wall-decal

This is very nice...but if it's not available Uppercase Living (UL) sells vinyl for your walls very similar to this and it looks as though it was painted. You can design your own as they have over 50 fonts & colors and a huge selection of UL designs & embellishments that will transform your space! (see example below) To check-out our catalogs: http://jeand.uppercaseliving.net
For a dandelion design use search box: http://jeand.uppercaseliving.net/Search.m