I'm unsure if this is a feature or bug but vanilla item frames don't render and use a significantly smaller item model than what is typical in vanilla. It may have something to do with the Create placard as the display model is of similar sizes.

This is a screenshot showcasing the (in order from left to right) the vanilla item frame, the Create placard, and the TiC clear item frame. Please excuse the crappy attempt to label things with Paint.

As you can see on the vanilla item frame, when compared to the TiC frame, there is a significant change in the model scaling.

I am not sure if this may be part of the included resource pack called Better Vanilla Building. Could you try disabling it and checking again?

Yup, just disable the BVB resource pack and they became visible, it also seems like I was wrong in assuming that the model size changed. For whatever reason TiC just scales the item models larger than typical. Everything in accordance, I'll close this issue.