Since the subject is a large business like McDonalds I did a brief research on the content but unfortunately I couldn't find any definitive information about the reality of the incident. Since Bitcoin and other cryptocurrencies aren't yet accepted as a legal payment method by many governments I honestly don't think that such a large business will accept payment with Bitcoin or other cryptocurrencies. For this reason I don't think that the information and images in the content can be correct. Additionally, I have some doubts that this post is not up-to-date because the full menu content is not visible and the amount paid corresponds to around 45 USD with today's prices.
Finally, I think that if a large business like McDonalds starts accepting payments with Bitcoin or other cryptocurrencies this information will be announced quite quickly through reliable sources. For this reason, I think this content isn't accurate as there are many questionable details about the current situation and it has not been verified by any reliable source.
I agree with you. I was also skeptical about this knowing that McDonalds is a massive international food chain. If they are accepting crypto payment (heck even just a few branches) I'm sure it will make noise and we will find a post here in the forum about it. Moreover, you have a good point regarding the legality of cryptocurrencies for a lot of countries, which is a big factor to consider before a big food chain like McDonalds incorporate it as an offical means of payment.
As for the picture posted, I think it was taken out of context. There are a lot of possibility on what could have happened there. For example, it could be that it just so happened that the phone was opened to that page and since the kid and whoever he was with was in front of the ordering machine it was misunderstood by the one who took the photo. Nevertheless, unless there is a legit verification as to what the actual facts are regarding the phone, I'd say it is not reliable to assume they are paying using BTC.