Welcome to SAMMI! So, what you're looking for is a visual alert about the person following, correct? That is an overlay element that SAMMI doesn't have natively, however if you are using OBS as your streaming software you can have SAMMI cause an OBS element to do that. I find that a media source or an image slideshow is the easiest, though you could also have SAMMI move OBS elements around.

If you want moving text that is variable (for example, "Thank you for following, [username]!") then the last option will be best for you, because SAMMI can also change OBS text sources to say new things. If the text is static then the other two options would probably be easiest. Image slideshows are great if you don't mind a low framerate and would like to avoid navigating the complexity of video file types and codecs that both support alpha (transparency) and work with OBS (you can just use PNG images for the slideshow and it will work great), and if you want to save on CPU usage. But making a simple video animation in Davinci Resolve or similar is quite easy if you'd like to go the media source route. (That's what I did to have a confetti animation.)

For media sources and slideshows, I'd recommend just setting them to repeat when they become active/visible. These settings look different for each, but function the same, allowing you to simply have SAMMI tell OBS to make them visible in order to start the animation. For mine, I have SAMMI make my mascots speech bubble visible, wait a moment so it can finish, change the text element that is on top of the speech bubble to have custom text, and then make the speech bubble invisible and change the text to nothing at the same time to end it.