let's see^^^^^ (and it's already covered in CM forum rules.)
it's none of the above...because it's a reactionQuestionable content - Some content issues are left to the discretion of the individual moderators, but may include any material that is knowingly false and/or defamatory, misleading, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, ***ually oriented, threatening, invasive of a person's privacy, that otherwise violates any law, or that encourages conduct constituting a criminal offense.
none of those because...it's a reactionFlaming, Bashing, and Trolling - Hate posts and personal attacks will not be tolerated on the Forums, as is posting topics specifically to provoke a negative response from someone (AKA trolling).
none of those...because it's not a post...it's a reactionSpam - Purposely spamming a message board with senseless, vacuous, or empty messages is highly frowned upon, unless posting in Everything else forums where spam is allowed .
as annoying as those are...it's not that...cause it's a reactionFlashing GIFs are not, under no cir***stances, to be used in signatures or posts. This can be dangerous to some users with Photo Sensitive Epilepsy and can cause serious harm.
remind me again where in the forum rule cm states that reaction bombing is an offense?