The "Information Box" slide type is excellent for when you want to say something about the background asset. Since the text (in default setting) is contained in a box with a background, and there is a small "call-out" animation, this is very usable for calling out stuff in the background.
Since the slide allows for all sorts of behavior manipulation, by turning animations of call-outs on and off and changing color and opacity on all elements, you can use it in a multitude of ways. It also takes quite a lot of text – so you can fit 180 characters in the Message field and a label text of 20 characters in addition to that.
You can place the box with the label at nine distinct positions on the slide, and for 16:9 and 9:16, that makes it possible to place the box "around" the subject in the background asset.
Usage and behavior
You have a lot of options on this slide. First of all, you can control the X- and Y-position of the box and label, which means you have nine different placement options for it.
You can also control the animation of the actual text in and out – which allows you to keep the same text over multiple slides if you need to change the background asset with the same text.
You have three different options for the call-out animation (four, if you include "None") that controls how the actual call-out looks.
And you have access to full color and opacity control of the boxes and the texts under "Color."
The Label field holds 20 characters in the Small typography.
The Message field holds 180 characters in the Small typography.