It does not seem that way. When I want to watch a DVD from my external drive I am presented with only two options: 'Open store' and 'take no action' . It may just be a setting on the computer.
Nevertheless, since you can see the files, just open the folder Video_ts and click on the first *.VOB file. you may be asked which app to open it with. In the time of streaming DVD are getting more and more obsolete and manufacturers adjusting to that....