Thank you all for your thoughts. You're right, fenifur - the top one is 1795. The other is 1806.
The 1806 signature of Hester Stroud is from her marriage entry. I thought it relatively uncommon for a woman living in the east end of London to sign her name. (Her husband made his mark.) And it was probably even less common in 1795?
Like you fenifur, my handwriting has changed over the years. In fact I often write in several different styles - sloping, straight up and down etc, and even form various letters differently. When rushing or not taking care, I can even stumble over some letters which makes them look different again.
With these signatures, the most obvious differences are the capital H and the s. I also think the small r's might differ. However looking closer, I can see some similarities.
The first instant I saw them together, I thought they were from the same hand. It was only when I looked closer that I had doubts. The H is formed in the same way minus the big loop at the start of the letter. The small o in both surnames look the same. The t's in Hester are both crossed similarly - with the same kind of curve/curl to the stroke (not straight). Both t's in Hester go straight down to the line and are not rounded at the bottom to go up to form the e. The way the es is formed looks the same in both signatures (slope is the same) but then the second s is rounder than the first.
How much of this comes down to the 'rules' for writing at the time, and the person's own style, I don't know.
I would be grateful for input from other rootschatters.