Samsung has evidently learned from its mistake with the 'S Pen design flaw' on the Galaxy Note 5, and has ensured the S Pen stylus cannot be inserted the wrong way around on the new Galaxy Note 7.
The design issue, which was also referred to as 'pen-gate' by many, allowed users to insert the S Pen stylus backwards in the Galaxy Note 5, which caused harm to components like the detection mechanism while also getting stuck in the slot. Samsung's just announced flagship, Galaxy Note 7, the company has ensured that you cannot insert the stylus in the wrong manner.
(Also see: How Is Samsung Galaxy Note 7 Still a Thing?)
In fact, as pointed out by Sammobile, the stylus stops at around 2-3mm mark when it is inserted in a wrong way. This measure by the company is likely to avoid it the hassle and the angry letters that it received in the case of Galaxy Note 5.
In addition, the company has also made S Pen water and dust resistant and improve the precision on the stylus with Galaxy Note 7.
The 'pen-gate' issue was highlighted to such a level that Samsung had to initially issue warnings on its phone and eventually even make changes to its mechanism to ensure that users didn't end up inserting the stylus backwards.The problem, as many users pointed out, was due to the fact that the top and bottom of the S Pen look almost identical in thickness, and therefore made users susceptible to the mistake.