Came here to say this. I'm deaf, if that isn't obvious with my screen name, but yes you're right, that's the "I Love You" sign, the one where you stick out your thumb, index finger and pinky finger out, while your middle and ring fingers are retracted into a "fist".

The reason why we do this is because in sign language, the letter "I" is signed with the pinky finger sticking out only, the letter "L" is signed with both the thumb and the index fingers sticking out only, and the letter "Y" is signed with both the thumb and the pinky fingers sticking out only.

You can see here by looking at the first letter of each word: https://thumbs.dreamstime.com/z/i-love-you-finger-spelling-american-sign-language-asl-i-love-you-phrase-finger-spelling-american-sign-language-asl-white-181904516.jpg

So it's a combination of letters signed out in one sign, "ILY", as seen here in the middle right picture: https://www.speechbuddy.com/blog/wp-content/uploads/2013/02/love-infographic-791x1024.jpg

With the thumb joining the middle and ring fingers in retracted form, to form the "horns" sign (only the index and the pinky fingers are sticking out), that's like the "rocker" or the "longhorns (Texas)" sign but yes I know, it has been used to symbolize the Devil as well.