Downvote from me.
FiM, EQG, TYT are all 2D CG / CGI so all screencaps of these shows are 2D CG / CGI.
CG just means Computer Graphics and CGI just means Computer Generated Image(ry). These are synonymous and while most modern CG/CGI is 3D, it doesn’t strictly have to be.
The proper term for added visual effects is VFX (Visual Effects). This also does not strictly mean CG/CGI, though in the modern era it pretty much always is.