Thanks to Joshua for this. If you can't see that sign, here is as close as I can get it without it being all distorted:
CAUTION MINIATURE HORSES ON BOARD.
That sign says there's multople mini horses in there. With the size and cuteness of the animals, there could be a party of like 13 hanging out in that van. Who woulda thought that barely-marked white vans would be a source of infinite joy? We best not let kids know this or they could get a twisted perception of reality. Not ALL white vans are like this. Always look for the mini horse sign.