Laser Scope
Laser Scope
[Box with a mailing label on one side, and in the front:] Miss your loved ones? [Picture of a laser scope.] YOU DON'T HAVE TO. RJX-21 Laser Scope

This comic plays on the homonymic relationship between "miss" (to feel sad due to the absence of someone) and "miss" (to fail to hit – in this case, with a gunshot). "Miss your loved ones?" is a question that would generally use the former "miss." However, its use on the package for a laser scope implies the latter "miss."
A sighting scope can be attached to a firearm to aid in aiming the weapon. The addition of a laser improves the accuracy of the weapon by making it easier to aim consistently. The model number RJX-21 does not appear to be a reference to anything, and this comic is primarily a play on a common marketing technique of adapting a common saying to your own product by use of homonym or homophone ; in this case, it is perhaps an inappropriate use, as one would not be expected to be aiming a firearm at their loved ones.  In real life, this would imply a serious family breakdown with extreme feelings of pain and revenge, which is actually a tragically sad story, not the normal fodder for a light-hearted joke.
The title text hammers it home with the dual use of the word "miss," as the writer wishes he had missed (failed in his attempt to shoot) someone so they would not miss them (feel bad that they are not there), implying that he shot a family member, and is now feeling the grief. The humor here is that the writer apparently still cares about his loved one, despite having attempted to shoot them in the past.
[Box with a mailing label on one side, and in the front:] Miss your loved ones? [Picture of a laser scope.] YOU DON'T HAVE TO. RJX-21 Laser Scope
