It is Google Adwords best practice when targeting mobile devices to write mobile relevant creative, whether that be mobile call to actions such as ‘call now’ or mentioning the user environment, e.g. ‘ on the go’.
Ebay, notorious for both excessive dynamic keyword insertion and also great seasonal ads, have really gone to town with mobile themed creative in their latest creative.
This is a great example of talking to your audience with the right tone. Users will hopefully appreciate this attention.