"GraphicsAlign" is a front end token that opens the Align Selected Graphics dialog box.
This token is equivalent to the menu command Cell Align Selected Graphics.
This token opens a dialog box that allows you to set the options ImageSize and ImageMargins on the selected cell objects. See Align Selected Graphics for more information.
To execute a front end token, you typically evaluate a command of the form FrontEndExecute[FrontEndToken[token]].