Picture won't change?!

Hi, I don’t know why I have added a woman photo to service section 3, then I add a link to that section in index-service.php to link to an another page, then the image changes to a candle image of section 1 instead?! But when I look at the link of the image in section 3 in Option Panel the link of the image is still correct. So, I don’t know how the image changes by itself, but the original image link is still the same?

My website is: http://beautyschool.online/
And as you can see on my website, the image of service section 1 and 3 are the same, but I have uploaded different photos to each section. Don’t know how that happens.

I thank you in advance!

Buppha