Might be load order, does betterlookinggarbs.mod have a dependencies section with "A Game of Thrones" in it? And are you using the BLG/AGOT compatibility submod along with it.
It could also be a conflict with other portrait submods.

Can you change the load order? There is a dependency with "A Game of Thrones", and I have also turned on the submod. And this is the only portrait mods I have.

The dependencies is how load order is set.
If there is a double extension betterlookinggarbs.mod.mod file delete that.

The dependencies are normal. And there is only one extension.

It's a problem with gfx/characters/shared/imprisoned.dds getting loaded with a mismatched frame count. Any other mods touching that?

No... At least, I don't think so. I only activate the AGOT, blgagot, and the normal blg, that's all.

Is it the workshop version of AGOT? Check if its .mod file contains
name = "A Game of Thrones"
and not something else.

It contains this:
name = "A Game of Thrones"
path = "mod/A Game of Thrones"
user_dir = "A Game of Thrones"
supported_checksums = { YSLL XSLL }
picture="steam_icon.jpg"
replace_path = "history/characters"
replace_path = "history/diplomacy"
replace_path = "history/provinces"
replace_path = "history/titles"
replace_path = "history/wars"
replace_path = "history/technology"
replace_path = "history/eu4_converter"
replace_path = "history/offmap_powers"
replace_path = "common/artifact_spawns"
replace_path = "common/artifacts"
replace_path = "common/bookmarks"
replace_path = "common/buildings"
replace_path = "common/cb_types"
replace_path = "common/combat_tactics"
replace_path = "common/council_positions"
replace_path = "common/council_voting"
replace_path = "common/cultures"
replace_path = "common/death"
replace_path = "common/death_text"
replace_path = "common/disease"
replace_path = "common/dynasties"
replace_path = "common/event_modifiers"
replace_path = "common/execution_methods"
replace_path = "common/game_rules"
replace_path = "common/government_flavor"
replace_path = "common/governments"
replace_path = "common/graphicalculturetypes"
replace_path = "common/heir_text"
replace_path = "common/holding_types"
replace_path = "common/job_actions"
replace_path = "common/job_titles"
replace_path = "common/landed_titles"
replace_path = "common/laws"
replace_path = "common/mercenaries"
replace_path = "common/minor_titles"
replace_path = "common/modifier_definitions"
replace_path = "common/nicknames"
replace_path = "common/objectives"
replace_path = "common/offmap_powers"
replace_path = "common/on_actions"
replace_path = "common/opinion_modifiers"
replace_path = "common/province_setup"
replace_path = "common/religion_modifiers"
replace_path = "common/religions"
replace_path = "common/religious_titles"
replace_path = "common/retinue_subunits"
replace_path = "common/save_conversion"
replace_path = "common/scripted_effects"
replace_path = "common/scripted_triggers"
replace_path = "common/societies"
replace_path = "common/special_troops"
replace_path = "common/trade_routes"
replace_path = "common/traits"
replace_path = "common/tributary_types"
replace_path = "common/triggered_modifiers"
replace_path = "gfx/flags"
replace_path = "events"
replace_path = "decisions"

Still looks like things should be. If you had an early version of blgagot before delete it and replace it with a clean install.

I use the one in steam workshop though. Or maybe I should reextract.

And it's now working perfectly after I reextract it. Hurray for miracles!