That is not normal procedure.

It sounds like the poll worker was hiding your voter registration signature so that you could not see it as you signed, perhaps thinking that way you could not "forge" the signature and thus "cheat" the system. Did you get the sense she was comparing your signature to the one in the book? Did you feel intimidated?

Because she absolutely should not be attempting signature verification. There is even a unanimous Pennsylvania Supreme Court ruling buttressed by a ruling by a Trump-appointed Federal District Court Judge that "...the Election Code does not permit county election officials to reject applications or voted ballots based solely on signature analysis..."

Further, if she was making an attempt to check signatures, her behavior falls dangerously close to voter intimidation. From the vote.pa.gov site under "Examples of Voter Intimidation": "Routine and frivolous challenges to voter's eligibility by election workers or private citizens that are made without a stated good faith basis."

It all comes down to, did you feel intimidated by her behavior? Because if you did, you can file a complaint - again on vote.pa.gov under "Your Rights/Report Election Complaints".

Here is a great CNN fact check article that has links to the judicial rulings. It is mostly about checking signatures for mail-in ballots, but it applies to in-person ballots as well. https://www.cnn.com/factsfirst/politics/factcheck_70c9f1b1-352d-405e-b625-f204161fd55a

tldr: Poll workers are not handwriting experts and shouldn't pretend to be.