Keep in mind that we live in a country where we are not allowed to buy and sell through bitcoin. Therefore he is selling the shirts in the fiat currency however all the shirts have Bitcoin logo over it. This is the maximum he can do to promote bitcoin. I hope when some day bitcoin may become a legal tender here also, then he can do the transactions in Bitcoin.
Link of the store is
https://store.ilmeaalim.com/en/
people or businesses who do really attached up these logos into their business to create or show some awareness which is really that good in overall adoption and recognition.
One of examples (online stores)
https://www.techinasia.com/bitcoins-spend-7-merchants-accepting-bitcoins-philippines
But if we do speak about international list then it would be good on reading this one out.
https://icoholder.com/blog/places-accept-bitcoin/
Recognition doesnt stop and it would really be keeping on progress on which we know that not all places or countries does have that similar approach specially if
government does really make out such opposing step, then as a business owner it is really hard to make out some integrations.