It's supposed to be informative of explaining to the punters their choice of destination ... "Ah Gran Canaria, it's in Spain so we can go there and visit our friends on the Costa Brava" ... "Oh no you can't because Gran Canaria ain't nowhere near to Spain nor the Costa Brava!"
Seriously?
So are we doing Stobart a disfavour by saying "Your website is sh1t, sort it out" or should we be saying "Everything is perfect, the sun shines out of your Stobart butt"?
No, your being a pedant, and while there is sometimes a time for pedantry, this isn't it. It's meant to be a quick guide as to what's available from SEN with the aim of getting more people to use the airport rather than a discussion on the international status of various territories.
What country would you suggest Tenerife is listed under?
You can guarantee that if they had commissioned unique photos for the website rather than using stock images, there'd be somebody on here moaning about the waste of money...