It should be just to the left of the Quote box. I am not sure what's there in smaller displays, though. I don't often log in on my cellphone. It's a responsive site so people on cellphones, tablets, and full-screen computer displays see different things, although most everything is still there somewhere, and mostly the changes are just a different arrangement. You won't see a "like" option for your own posts, however.
I figured it all out... I was using a default format on phone and computer . Once i changed that the whole thing changed.. more color on the page, colored boxes and tiny thumbs .. the works. I never knew about this format i guess,.Much better alos.
For a moment yesterday, I didn't have a "Like" button either. I was logged in so it confused me. Then I refreshed the screen and it was there. I'm still confused by it but it hasn't reoccurred.