Yes you can watch Netflix on a mobile hotspot.
Although watching Netflix uses a lot of data so if you have a mobile hotspot with limited data then you could blow through the hot spot data really quick.
A 1 hour movie on Netflix can use as much as 1 GB of data.
So if you have a Straight Talk Mobile Hot Spot and have 1 GB of data for the plan then you would use that 1 GB of data by watching just 1 Netflix movie.
That would mean that the Netflix movie would cost you the $15.00 per movie for the data.
So while Netflix and other movies can be streamed on a mobile Hot Spot it's not the best thing to use to watch Netflix or other movies.
I have a Straight Talk Mobile Hot Spot and it's a wonderful device but I use it for checking email or writing a blog post when I'm away from my normal DSL internet.
I pay $45.00 per month for my Centurylink DSL for unlimited data which is cheaper than using the hot spot.