Targeted upvoting – i.e., upvoting because of the poster instead of the post itself – is forbidden on the entire network and can have unpleasant consequences both for the voter and the votee.
While going through a specific user's posts out of curiosity (and naturally upvoting several posts as a result) and going through a specific user's posts with the intent of finding something to upvote are very hard to distinguish for an observer, the latter is targeted voting and thus not allowed.
In this specific case
Answers that do not make any assumptions can be easily tested by replacing our user IDs with others'. Other answers will require a bit more tinkering, but should still remain testable by querying other SE sites apart from PPCG.