That's a nice looking, and very clearly, smallmouth...
Two ways you distinguish it beyond the stripes/bars vs lines:
1. The easiest is by the depth (or lack of depth) in the notch on its dorsal fin. On a largemouth, the notch goes deeper (all the way to the back / body) vs a smallmouth which is much shallower
2. The jawline does not extend beyond the eye. If you look at a bass from tip of mouth to the gills, corner of the jaw is in FRONT of the eye (closer to the tip of the mouth). In a largemouth, the jaw line is beyond the eye line. Thus, the bigger mouth....
Here is a link:
https://fishingbooker.com/blog/smallmou ... outh-bass/