It is completely normal to need a moment to orient yourself. Start with the title, axes, units, legend, and any footnotes. Those elements usually explain most of what initially feels confusing.
If one part is genuinely ambiguous, a focused clarification question is fine. The key is to ask about the information, not to outsource the interpretation. For example, clarifying what a category represents is different from asking the interviewer what the chart means.
Once you understand the mechanics, look for the biggest pattern before diving into detail. A strong first observation often gives you a direction for the rest of the analysis.
Do not panic because the exhibit did not make sense instantly. Taking 15 or 20 seconds to understand it properly is usually better than speaking too early and building your answer on a misread chart.