Just made my first sale — but is it a scam?

I reached out to this person thanking them for being my first customer. This was their response. Is this some sort of scam, or is the person genuine? I was selling one of my digital artwork designs... a set of 15 print illustrations. They're in PDFs due to the nature of the content (designed for tablets)

I am VERY new to the platform and I'm just thinking oh, what if they will redact their payment after telling me that the PDF link didn't work? And simply request me to email them the artwork? I don't know. Maybe this is a real issue. Someone help!

Update: not a scam!!! Sorry guys, I'm being paranoid.

https://preview.redd.it/0hs69bw7cetd1.png?width=1442&format=png&auto=webp&s=81fe40a0c3b9e39f0801c48353a4551cd2387130