Well, you could exert a modicum of effort and actually read my blog. I’m feeling generous today, so I’ll enact the effort to spoonfeed you:
Transfats experience privilege that they should not have, they were born with a disabled, thin body, and not the full, complete body that their mind assumes to be. Being stuck with this privilege is oppressive. Transfats also witness and to a degree, also undergo the experiences of fat people and the oppressiveness of fat-hate culture.
This concept is known as oppression multiplicity, where forces from multiple directions can affect a trans* that hasn’t transitioned.