For everybody who is not taking HRT of any kind, your hormone levels peak in the late teens and early 20's, then slowly decrease as we age. This is the normal experience and is primarily responsible for the changes in our appearance as we age.
It is really hard to make a generalized statement about how HRT makes us look different, but many people will notice significant changes depending on which hormone you are taking. If you are on Estradiol, you will appear younger than your real age. If you are on Testosterone, you will maintain muscular strength and appearance, but not really a youthful appearance. This has more to do with the results of HRT than any age reversing. Those of us who started HRT later in life, see the changes more than someone who started as a teen.
From my picture, you can see how I look. I am 68 and I have been on HRT for 3 & 1/2 years. Many people say that I look like I am in my 50's. Thank you very much.

There are other factors that affect aging. Sun exposure and smoking tobacco are the biggest ways to age faster.