Add another image than logo in woocommerce pdf invoices

Hello everybody,

I am wondering if there is a way to add another image in the .pdf ?

I tried in the template:

https://i.imgur.com/d5qQQcD.png

But I just get an empty square:

https://i.imgur.com/9bb0YiR.png

I also tried for test purpose a cheeky trick with a function:

https://i.imgur.com/jJog3zN.png

But the result is the same:

https://i.imgur.com/z8FMDPI.png

I manage to have everything setup and working fine but I need this image that will be a signature/stamp.

Thanks in advance, for whoever will be reading me and hopefully have an answer :)

lolo