A caller is a specific button of Infinite Content that enables to open the iframe window when configuration is not set as automatic. There are two types of callers, the differences of which are pointed out in this article.
Static caller or button type
If you choose Static in the drop-down option Behaviour, provided in the Caller submenu of the Properties panel of Infinite Content, the caller will behave as a button. A use of a button implies that design will resize together with the player, either if it enlarges or reduces. This is to say that if the video is reproduced on a small screen, the button will reduce as well. Besides, as it acts as a button, the hover is available, for Multidevice and Desktop projects, and the option will be enabled when you choose the Add States option and assign an image to Hover.
Dynamic caller or pointer type
If you choose the Pointer behaviour option on the Caller submenu, it will behave as a pointer with which it is possible to interact. It may seem there are no differences apparently, but the pointer does not scale its size when screen dimensions where the video is reproduced vary. Since it is not a button, the hover effect is not available.