I have a feeling that the Phone conversations over rattly lines usually are the real Trump, whereas a lot of video interviews are done with doubles.

The doubles are how Trump can be so active, but explains some inconsistency between different Trumps if you really analyse and compare them. Though, Trump's distinctive almost cartoonish look and demeanor certainly makes it easier to produce workable doubles than the visage of Bidens does.

The phone Trump is obviously calling from a secure location, perhaps the same place he batch films his video responses to things going on.