You can easily change this label and set the desired text you would like to display. In order to do this, please, please perform the following:
Go to Administration -> Labels and Messages
Filter the labels by type by clicking on the Library
link on the right-hand side of the page.
Type Select image
in the search field in order to find the label.
From the search results list click on the label with Resource key : SelectImage
and the label will open in edit mode.
Enter the desired text message in the text field and save the changes.
If you change the labels and messages for a first time you need to restart the application in order for the changes to take effect.
I am sending attached a short video for your convenience demonstrating the above steps.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Sitefinity CMS Ideas&Feedback Portal
and vote to affect the priority of the items