There is that-when the same artist works for more than one company.
Also if an image is in the public domain...it is fair game for anyone to use.
As for PSX and PB...I noticed it years ago. I can't remember now which ones...if I do I'll try to post links. I remember having the conversation in my LSS about it and they said yes they saw it too. The reason at the time I even thought about it was PB's angel policy at the time said you could only use THEIR product on a card which I found ironic. (since changed)
But the joke is on me today. MFT's new release has background stamps that immediately put to mind one I have...bc when it first came out...I was amazed at what Sandy Allnock did with it and started a thread about envisioning. Well...turns out...it was THEIRS! LOL. Etched flowers:
Original
new release (BTW a number of very beautiful flowers imho) :
But actually at this point, everything looks the same to me! LOL