Well you only have to look at Euopa Park as an example. They have Ed Euromaus as the profile pic for many of their social media channels (along with the flag of the country the channel is aimed at in the background). I think it does help brand identity somewhat, but I also feel it gives a more fun and personal feel to the brand, because people aren’t associating the park with a corporate logo etc. Another example could be Efteling and their mascot, Pardoes, who seems to be featured quite prominently in their marketing.