The tag alias #73660 thour_(meme) -> sour_face has been rejected.

Reason: They're the exact same thing. Even the (?) pages are almost identical.

EDIT: The tag alias thour_(meme) -> sour_face (forum #424178) has been rejected by @spe.

Not quite the same thing. thour_(meme) is referring to a particular meme where a character licks a lemon and their whole face collapses in on itself:
post #4966429 post #5014904

A sour_face can be a normal scrunched up facial expression from tasting something sour:
post #4721569 post #3671122

thour_(meme) is based on a comedic over-exaggeration of a sour face.

Several of the current thour examples are not faces.
post #4828361 post #4775521 post #4779274

The tag alias thour_(meme) -> sour_face (forum #424178) has been rejected by @spe.